W hole Numbers WHOLE NUMBERS T PO R PASS www.mathletics.co.uk It is important to be able to identify the different types of whole numbers and recognise their properties so that we can apply the correct strategies needed when completing calculations. 1 1 1 1 1 2 1 1 3 4 3 6 1 4 1 Pascal's Triangle Blaise Pascal developed this triangle 1 5 10 10 5 1 by simply adding two whole numbers together each time 1 6 15 20 15 6 1 1 1 1 7 8 21 9 28 36 35 56 35 70 21 56 7 28 84 126 126 84 is Give th Q 1 8 36 1 9 1 a go! The ant nest below has a tunnel system that leads down to a main chamber. After one ant enters the tunnel from the top, how many different ways can it get to the main chamber if it only travels downwards the entire way? Main Chamber Work through the book for a great way to solve this Whole Numbers Mathletics Passport © 3P Learning H 3 SERIES TOPIC 1 How does it work? Whole Numbers Place values 142 M illi o H u ns nd Te red ns s o f o T h f t h t ho ou ou us a s Hu and san nds nd s ds Te red ns s On es Numbers can be separated into columns that represent different multiples of 10. The column where a number is found determines the place value of that number. ×1 × 10 × 100 × 1000 × 10 000 × 100 000 × 1 000 000 NU MB E R S Remember: When multiplying by multiples of 10, just add the same number of zeros to the end 2 # 100 = 200 5 # 100000 = 500000 11 # 10000 = 110000 What is the place value of 4 in the number 34 250? Method 1: Multiplying the number by the multiple of 10 matching its position in the number 34 250 4 is in the thousands position Identify the position of the 4 in the number Multiply 4 by the place value ` 4 # 1000 ` place value of 4 is 4000 Method 2: The place value of a number can also be found by changing all the other numbers to a 0 34 250 04 000 Change all the other numbers to a zero ` place value of 4 is 4000 2 H 3 SERIES TOPIC Whole Numbers Mathletics Passport © 3P Learning Ignore all zeros in front of the 4 How does it work? Whole Numbers Multiplying the number by the multiple of 10 matching its position in the number. Hu nd Te reds ns o o f T h f t h t ho ou ou us a Hu sand san nds nd s ds Te reds ns On es (i) Write 631 405 using words (ii) Write 631 405 in expanded form ×1 × 10 × 100 × 1000 × 10 000 × 100 000 631405 (i) Using words: Six hundred and thirty one thousand, four hundred and five Name using groups of three (ii) Expanded form:^6 # 100 000h + ^3 # 10 000h + ^1 # 1000h + ^4 # 100h + ^0 # 10h + ^5 # 1h Multiply each number by the place value and add together Here is another example. 1 0 7 2 1 3 8 × 1 000 000 × 100 000 × 10 000 × 1000 × 100 × 10 ×1 M illi o Hu ns nd Te red ns s o f o Th f th tho ou ou us a s Hu and san nds d nd s s Te red ns s On es (i) Write 1 072 138 using words (ii) Write 1 072 138 in expanded form (i) Using words: One million, seventy two thousand, one hundred and thirty eight Name using groups of three (ii) Expanded form: ^1 # 1 000 000h + ^0 # 100 000h + ^7 # 10 000h + ^2 # 1000h + ^1 # 100h + ^3 # 10h + ^8 # 1h Multiply each number by the place value and add together Whole Numbers Mathletics Passport © 3P Learning H 3 SERIES TOPIC 3 How does it work? Your Turn Whole Numbers Place value 1 Write down the place values for each of these numbers a 1426 b 42 603 Place value of 1: Place value of 3: Place value of 2: Place value of 4: d 7 380 261 c 560 142 Place value of 5: Place value of 7: Place value of 6: Place value of 8: Write each of these ordinary numbers in: (i) worded form (ii) expanded form 2 a 2560 (i) Two thousand, five hundred and sixty (ii) (2 # 1000) + (5 b # 100) + (6 # 10) 1 306 211 (i) (ii) c 891 026 (i) (ii) 4 H 3 SERIES TOPIC Whole Numbers Mathletics Passport © 3P Learning How does it work? Your Turn Whole Numbers Place value d E NUMB OL 708 002 (i) Place Value ..../...../20... E NUM OL (ii) e 9 011 060 S * WH ER RS * WH E B (i) (ii) 3 Write the ordinary number for each of these: a Four hundred and thirty nine thousand, two hundred and six b ^4 # 1000000h + ^2 # 100000h + ^0 # 10000h + ^1 # 1000h + ^0 # 100h + ^3 # 10h + ^0 # 1h c Eighty one thousand and five d ^9 # 10000h + ^8 # 1000h + ^9 # 100h + ^9 # 10h + ^8 # 1h e Any number whose place values for 4, 5 and 2 are 4000, 5 and 200 f Three million, thirty thousand and thirty Whole Numbers Mathletics Passport © 3P Learning H 3 SERIES TOPIC 5 How does it work? Whole Numbers Adding and subtracting large numbers When adding or subtracting large numbers, make sure the place values are lined up correctly. Here are some addition examples to refresh your memory. Calculate 13 829 + 4271 13 829 + 4271 = = 13 8 2 9 + 41 21 7 1 1 Ensure matching place values are aligned 13 8 2 9 + Carry over the 'tens' value 41 21 7 1 1 18 1 0 0 ` 13 829 + 4271 = 18100 You can check your answer by simply entering the sum into your calculator. Always check that your answer makes sense if using a calculator. It is easy to accidentally press a wrong button when entering numbers and operations into a calculator. Calculate 317 293 + 20 011 + 102 356 317 293+ 317 293 + 20 091 + 102 356 = 2 0 0 9 1 102 356 317 2 9 3+ = 20 0 9 1 1 0 2 32516 Ensure matching place values are aligned Carry over the 'tens' value 439 7 4 0 ` 317293 + 20091 + 102356 = 439740 3 1 7 2 9 3 6 H 3 SERIES TOPIC + 2 0 0 9 1 + 1 0 2 3 5 6 Whole Numbers Mathletics Passport © 3P Learning = 439 740 How does it work? Whole Numbers There are many different accurate ways to subtract large numbers. You should always use the method that you were taught or know best. Here is an example using one way. Calculate 7635 – 4829 Step 1: 7 6 3 5 – 1 1 4 8 2 9 Line up matching place values Step 2: 7 6 3 5 – 1 1 4 8 2 9 Since 5 1 9 we cannot subtract, ` place a 1 between 5 and 2 The 1 is in front of the 5 (in the tens position), making it 15 The 1 is added to the 2 to make it 3 as ‘payback’ for using the 1 to make 15 Step 3: 7 6 3 5 – 1 1 4 8 2 9 0 6 15 – 9 equals 6 and 3 – 3 equals 0 Step 4: 7 6 3 5 – 1 1 4 8 2 9 0 6 Since 6 1 8 we cannot subtract, ` place a 1 between 4 and 6 7 6 3 5 – 1 1 4 8 2 9 2 8 0 6 16 – 8 equals 8 and 7 – 5 equals 2 Step 5: The 1 is in front of the 6 (in the tens position), making it 16 The 1 is added to the 4 to make it 5 as ‘payback’ for using the 1 to make 16 ` 7635 - 4829 = 2806 7 6 3 5 – 4 8 2 9 = Whole Numbers Mathletics Passport © 3P Learning 2806 H 3 SERIES TOPIC 7 How does it work? Whole Numbers Here is another example for subtraction. Calculate 38 234 – 21 576 Step 1: 3 8 2 3 4 – 2 1 5 7 6 Line up matching place values Step 2: 3 8 2 3 4 – 1 2 1 5 7 6 Since 4 1 6 we cannot subtract, ` place a 1 between 7 and 4 The 1 is in front of the 4 (in the tens position), making it 14 The 1 is added to the 7 to make it 8 as ‘payback’ for using the 1 to make 14 Step 3: 3 8 2 3 4 – 1 2 1 5 7 6 8 14 – 6 equals 8 Step 4: 3 8 2 3 4 – 1 1 2 1 5 7 6 8 Since 3 1 8 we cannot subtract, ` place a 1 between 3 and 5 The 1 is in front of the 6 (in the tens position), making it 13 The 1 is added to the 5 to make it 6 as ‘payback’ for using the 1 to make 13 Step 5: 3 8 2 3 4 – 1 1 2 1 5 7 6 5 8 13 – 8 equals 5 Step 6: 3 8 2 3 4 – 1 1 2 1 5 7 6 5 8 Since 2 1 6 we cannot subtract, ` place a 1 between 2 and 1 The 1 is in front of the 2 (in the tens position), making it 12 The 1 is added to the 1 to make it 2 as ‘payback’ for using the 1 to make 12 Step 7: 3 8 2 3 4 – 1 1 2 1 5 7 6 1 6 6 5 8 12 – 6 equals 6, 8 – 2 equals 6, 3 – 2 equals 1 Do all the subtractions since there are no more columns with the top 1 bottom ` 38234 - 21576 = 16658 3 8 2 3 4 8 H 3 SERIES TOPIC – 2 1 5 7 6 Whole Numbers Mathletics Passport © 3P Learning = 16 658 How does it work? Your Turn Whole Numbers Adding and subtracting large numbers 1 Calculate each of these addition questions showing all working. a 5 6 2 1 0 + 8 8 3 5 3 0 6 1 4 b 7 1 4 0 0 + 1 0 8 0 9 4 2 0 1 Large Whole Numbers c e 2 9 9 + 4 3 2 1 8 6 4 2 2 4 6 3 3 9 5 7 2 1 9 1 6 9 d 9+ 1 0 3 f ..../...../20... 8 4 3 + 1 9 5 6 0 4 6 3 8 7 6 3 2 9 3 1 0 3 4 1 8 + 1 5 2 Combo Time! Calculate the sum (+ ) of three hundred and forty five thousand, two hundred and nine and eighteen thousand, seven hundred and ninety six. Whole Numbers Mathletics Passport © 3P Learning H 3 SERIES TOPIC 9 How does it work? Your Turn Whole Numbers Adding and subtracting large numbers 3 4 Calculate each of these substraction questions showing all working. a 5 2 6 8 – 2 3 5 2 b 2 5 2 7 2 – 5 6 4 0 c 3 6 5 2 6 8 – 1 0 4 8 2 d 5 4 3 2 1 – 1 2 3 4 5 e 2 0 3 0 4 0 – 1 0 2 0 3 f 7 0 0 0 0 – 2 6 7 8 9 Combo Time! Calculate the difference (–) between: five hundred and seventy thousand, two hundred and seventeen and ninety eight thousand, four hundred and twenty one 10 H 3 SERIES TOPIC Whole Numbers Mathletics Passport © 3P Learning How does it work? Whole Numbers Long multiplication As you did when adding and subtracting, keep your place value columns lined up neatly. You need to be aware of the place value of the number you are multiplying by. Calculate 1429 # 32 1 4 2 9 3 2 +1 2 8 4 8 # 1 4 2 3 2 8 5 +1 +2 3 2 6 7 9 2 8 0 1 4 2 3 2 8 5 4 2 8 7 4 5 7 2 9 # 2 8 + 0 8 Line up matching place values Multiply the 1429 by 2 Carry over any ‘tens’ values after multiplying # For 1429 # 3 tens, put a 0 in the ones column and multiply by 3 Carry over any ‘tens’ values after multiplying Add the two new numbers together ` 1429 # 32 = 45728 Here is another example. Be careful to line up the columns correctly. Calculate 423 # 506 4 2 3 5 0 6 +1 +1 2 4 2 8 # 4 5 2 5 0 0 0 2 0 3 0 3 6 8 0 4 5 2 5 0 0 0 +1 +1 2 0 0 5 2 0 3 0 0 3 6 8 0 0 4 5 2 5 0 0 0 +1 2 1 1 5 2 1 4 0 2 0 3 0 0 3 3 # 6 8 + 0 0 8 Line up matching place values Multiply the 423 by 6 Carry over any ‘tens’ values after multiplying # For 423 # 0 tens, put a 0 in the ones column first and multiply by 0 # For 423 # 5 hundreds, put a 0 in the ones and tens columns and multiply by 5 Carry over the ‘tens’ value after multiplying Add the two new numbers together ` 423 # 506 = 214038 Whole Numbers Mathletics Passport © 3P Learning H 3 SERIES TOPIC 11 How does it work? Your Turn Whole Numbers LE NUM HO Long multiplication RS * W E B MultipLlong ication 1 0 1 2 3 7 e 12 H 3 SERIES TOPIC # 2 0 2 0 2 1 5 f Whole Numbers Mathletics Passport # 3 8 7 6 4 5 d # © 3P Learning /20... LE NUM HO 9 5 7 0 6 3 c ..../..... RS * W BE Calculate each of these multiplication questions showing all working. Check your answers on the calculator. a 3 0 1 6 # 2 5 8 1 b 2 1 1 9 1 # # How does it work? Your Turn Whole Numbers Long multiplication 2 Calculate each of these multiplication questions showing all working. Check your answers on the calculator. a c e 2 1 2× 1 2 1 b 9 0 8× 2 0 9 8 6 4× 3 4 5 6 4 8 5× 1 2 3 d 1 3 2 5× 4 3 7 f Whole Numbers Mathletics Passport 2 5 8× 4 0 5 © 3P Learning H 3 SERIES TOPIC 13 How does it work? Whole Numbers Short and long division Short and long division are only different due to the size of the number you are dividing by. Here is a short division question. Calculate 75 408 ' 6 1 6g 7 1 5 4 0 8 Step 1: Divide 7 by 6 Put the whole number answer (1) above the 7 Make the remainder (1) the ‘tens’ digit for the next number 1 2 6g 7 1 5 3 4 0 8 Step 2: Divide 15 by 6 Put the whole number answer (2) above the 5 Make the remainder (3) the ‘tens’ digit for the next number 1 2 5 Step 3: 6g 7 5 4 0 8 Divide 34 by 6 Put the whole number answer (5) above the 4 Make the remainder (4) the ‘tens’ digit for the next number 1 2 5 6 Divide 40 by 6 Put the whole number answer (6) above the 0 Make the remainder (4) the ‘tens’ digit for the next number 1 4 3 Step 4: 6g 7 1 5 3 4 4 0 4 8 Step 5: 1 2 5 6 8 6g 7 5 4 0 8 1 3 4 Divide 48 by 6 Put the answer (8) above the 8 4 ` 75 408 ' 6 = 12 568 remainder fraction = If there is a remainder at the end, always write it as a fraction. the amount left over the divisor Calculate 518 ' 3 Step 1: 111 2 333ggg555 22111888 Divide 5 by 3 Put the whole number answer (1) above the 5 Make the remainder (2) the ‘tens’ digit for the next number Step 2: 111 777 2 333ggg555 22111888 Divide 21 by 3 Put the whole number answer (7) above the 1 There is no remainder this time Step 3: 111 777 222 323232 2 333ggg555 22111888 divisor amount left over Divide 8 by 3 Put the whole number answer (2) above the 8 Write the remainder as a fraction ( 23 ) to the right ` 518 ' 3 = 172 23 14 H 3 SERIES TOPIC Whole Numbers Mathletics Passport © 3P Learning How does it work? Whole Numbers Here is a long division question. Calculate 6259 ' 14 Step 1: 4 14 g 6 2 5 9 5 6 Step 2: Step 3: Step 4: Step 5: 4 14 g 6 2 5 9 5 6 6 5 4 14 g 6 2 5 6 6 5 4 5 9 4 14 g 6 2 5 6 6 5 4 5 9 5 6 5 6 9 9 4 4 7 14 g 6 2 5 9 5 6 6 5 5 6 9 9 9 8 Step 6: 4 14 g 6 2 5 6 6 5 4 7 5 9 5 6 9 9 9 8 1 Divide 62 by 14 Put the whole number answer (4) above the 2 Multiply 14 by the answer (4) and write this underneath the 62 Subtract 56 from 62 Drop the 5 down next to the answer Divide 65 by 14 Put the whole number answer (4) above the 5 Multiply 14 by the answer (4) and write this underneath the 65 Subtract 56 from 65 Drop the 9 down next to the answer Divide 99 by 14 Put the whole number answer (7) above the 9 Multiply 14 by the answer (7) and write this underneath the 99 Subtract 98 from 99 Write the remainder as a fraction 1 ` 6 259 ' 14 = 447 14 Whole Numbers Mathletics Passport © 3P Learning H 3 SERIES TOPIC 15 Whole Numbers Short and long division a 4767 ' 3 b 6180 ' 5 g c g 6912 ' 4 d 12 054 ' 6 g 2 g Calculate each of these short division questions showing all working. (psst: remember to write any remainders as a simplified fraction) Check your answers on the calculator. a 8965 ' 7 b 3879 ' 2 g c g 9263 ' 8 d 5801 ' 6 g 16 g H 3 SERIES TOPIC Whole Numbers Mathletics Passport © 3P Learning Short & DivisioLong n ..../..... RS * W BE Calculate each of these short division questions showing all working. Check your answers on the calculator. 1 LE NUM HO RS * W BE Your Turn /20... LE NUM HO How does it work? How does it work? Your Turn Whole Numbers Short and long division 3 Calculate each of these long division questions showing all working. Check your answers on the calculator. 15 g 3 8 5 5 c 24 5 1 8 5 a g b 23 g8 9 4 7 d 17 g2 5 7 8 Whole Numbers Mathletics Passport © 3P Learning H 3 SERIES TOPIC 17 How does it work? Whole Numbers Divisibility tests Divisibility tests are used to see if a small whole number will be a factor of a larger composite number. A number is always divisible by 2 if the last digit is an even number (i.e. 0 , 2 , 4 , 6 or 8) 234 is divisible by 2 as the last digit (4) is even A number is always divisible by 3 if the sum (+) of all its digits is divisible by 3 234 is divisible by 3 because 2 + 3 + 4 = 9 (which is divisible by 3) A number is always divisible by 4 if the number formed by the last two digits is divisible by 4 1324 is divisible by 4 because the last two digits form the number 24 (which is divisible by 4) A number is always divisible by 5 if the last digit of the number is a 0 or 5 265 is divisible by 5 because the last digit is a 5 A number is always divisible by 6 if it is divisible by both 2 and 3 234 is divisible by 6 because it is even (so divisible by 2) and 2 + 3 + 4 = 9 (which is divisible by 3) A number is always divisible by 8 if the number formed by the last three digits is divisible by 8 1328 is divisible by 8 because the last three digits form the number 328 (which is divisible by 8) A number is always divisible by 9 if the sum (+) of all its digits is divisible by 9 234 is divisible by 9 because 2 + 3 + 4 = 9 (which is divisible by 9) A number is always divisible by 10 if the last digit of the number is a 0 1840 is divisible by 10 because the last digit is 0 Investigate the divisibility tests for 7 and 11. They are a little more involved but interesting! 18 H 3 SERIES TOPIC Whole Numbers Mathletics Passport © 3P Learning How does it work? Your Turn Whole Numbers Divisibility tests Use the divisibility tests to determine whether each of these numbers are divisible by the numbers listed on the right hand side. Draw a line to all the numbers each one is divisible by. The first number is completed for you. 2 620 136 3 96 4 1491 345 5 207 6 512 588 8 738 9 1 001 001 312 756 10 8640 ..../..... /20... FOR NU 6030 S Y TEST IT 12 871 ISIBIL IV ERS * D MB Whole Numbers Mathletics Passport © 3P Learning H 3 SERIES TOPIC 19 How does it work? Whole Numbers Index notation for numbers Index notation uses a small number called a ‘power’, ‘index’ or ‘exponent’ to show how many times a number is multiplied by itself. Simplify these products by using index notation and then calculate: (i) 4 # 4 4 # 4 = 42 = 16 Two 4s in the multiplication, so the index is 2 We say ‘4 squared’ When a number is multiplied by itself once, this is called squaring the number (ii) 2 # 2 # 2 2 # 2 # 2 = 23 =8 Three 2s in the multiplication, so the index is 3 We say ‘2 cubed’ When a number is multiplied by itself twice, this is called cubing the number. The same pattern continues for any number of multiplications (iii) 3 # 3 # 3 # 3 # 3 # 3 3 # 3 # 3 # 3 # 3 # 3 = 36 = 729 Six 3s in the multiplication, so the index is 6 We say ‘3 to the power of 6’ A mixture of numbers multiplied together can also be simplified using index notation (iv) 4 # 5 # 5 # 5 # 4 # 5 Group identical numbers 4#5#5#5#4#5 = 4#4#5#5#5#5 = 42 # 5 4 = 16 # 625 = 10 000 We say ‘4 squared times 5 to the power of 4’ Doing the reverse to simplifying is called expanding. Write these in expanded form: (i) 74 74 = 7 # 7 # 7 # 7 The index is 4, so four 7s multiplied together (ii) 97 97 = 9 # 9 # 9 # 9 # 9 # 9 # 9 The index is 7, so seven 9s multiplied together Be careful: A lot of people make this mistake: 74 = 7 # 4 , which is NOT true. 74 ! 7 # 4 Make sure you can see the difference. 20 H 3 SERIES TOPIC Whole Numbers Mathletics Passport © 3P Learning How does it work? Your Turn Whole Numbers a 5 # 5 c 2 # 2 # 2 # 2 # 2 e 7 # 7 # 7 # 7 # 7 2 b # 7 4 # d 11 f 3 4 # # ..../..... # 4 11 # 11 3 # 3 # /20... # 3 # 11 3 # 3×3 # 3 # 2 Write each of the mixed products using index notation and then calculate. a 2 c 6 e 2 3 ION * I T A Write each of these products using index notation. EX NOT ND 1 ION * I AT EX NOT ND Index notation for numbers # # # 2 6 8 # # # 2 6 8 # # # 3 6 2 # # # 3 7 8 # # 7 8 # # 7 8 b 5 # d 2 # 1 # 2 # 1 # 2 4 # 3 # 3 # 4 # 3 f 5 # 4 # 4 # 2 # 2 Change each of these to expanded form. 4 8 a 33 b c 65 d 127 e 53 # 72 f 2 4 # 32 g 75 # 2 4 h 2 4 2 2 # 3 # 5 Whole Numbers Mathletics Passport © 3P Learning H 3 SERIES TOPIC 21 How does it work? Your Turn Whole Numbers Puzzle Time 2 units The area of a square can be written using index notation: 2 units Area = 2 # 2 = 22 units 2 = 4 units 2 62 Using each of the different grey squares below twice and the black square only once, form a rectangle on the grid above. You can do this by shading in the squares using a pencil or cut some similar-sized squares out of another sheet of paper and try to complete like a jigsaw. The top left-hand corner of the rectangle is already completed for you, so only one more 62 grey square can be used. 12 32 use twice 42 52 62 use once use twice use twice use twice When finished, have a go at writing two different expressions for the total area of the rectangle using index notation. Hint: For one expression multiply the side lengths together. Area expression 1 22 H 3 SERIES TOPIC Area expression 2 Whole Numbers Mathletics Passport © 3P Learning How does it work? Whole Numbers Square roots and cube roots Finding the square root or cube root of a number is the opposite operation to squaring or cubing. The radical symbol ( ) is used for roots, with used for square root and 3 for cube root. The square root sign is asking: What number multiplied by itself once will get the number inside me? Calculate the square root of these whole numbers (i) 9 9 =3 Because 3 # 3 = 32 9 = 3#3 =9 32 = =3 or (ii) 36 9 written as a product of its prime factors 36 = 6 36 = 6 # 6 Because 6 # 6 = 62 = 36 36 written as a product of its prime factors 62 = We look closely at prime factors next = 6 The cube root sign is asking: What number multiplied by itself twice will get the number inside me? Calculate the cube root of these whole numbers (i) 8 3 or 8 = 2 3 8 =3 2 # 2 # 2 Because 2 # 2 # 2 = 23 = 8 = 3 8 written as a product of its prime factors 23 = 2 33 The little ‘root’ number indicates how many times the same number appears in the multiplication. (ii) 343 3 or 343 = 7 3 343 = 3 7 # 7 # 7 Because 7 # 7 # 7 = 73 = 343 = 3 343 written as a product of its prime factors 73 = 7 You could be asked to write a value using square or cube root notation. Rewrite these numbers (i) 4 as a square root 42 = 4 # 4 = 16 ` 4 = 16 (ii) 3 as cube root 33 = 3 # 3 # 3 = 27 ` 3 = 3 27 Whole Numbers Mathletics Passport © 3P Learning H 3 SERIES TOPIC 23 Your Turn Whole Numbers LE NUM HO Square roots and cube roots a 4 b 16 c 25 d 49 e 81 f 121 2 Calculate each of these cube roots a 3 27 b c 3 216 d 3 3 a 3 c 6 512 b 8 d 12 Write each of these values using cube root notation a 1 b 2 c 5 d 7 24 64 Write each of these values using square root notation 4 3 H 3 SERIES TOPIC Whole Numbers Mathletics Passport © 3P Learning RS * W BE Calculate each of these square roots ..../..... RS * W BE 1 Squa & Cubree roots roots /20... LE NUM HO How does it work? Where does it work? Whole Numbers Factor Trees Composite numbers can be divided exactly (with no remainder), by other smaller or equal whole numbers called factors. Composite numbers: 15 9 1 , 3 , 5 , 15 Factors: 12 1 , 3 , 9 1 , 2 , 3 , 4 , 6 , 12 4 24 1 , 2 , 4 1 , 2 , 3 , 4 , 6 , 8 , 12 , 24 Prime numbers only have 1 and themself as factors. 2 3171131 Prime numbers: 1 , 2 Factors: 1 , 3 1 , 17 1 , 11 1 , 31 All composite numbers can be written as the product ( # ) of prime factors (all the prime numbers that divide exactly into them). Let’s see how. ‘Express’ is a another way of saying ‘write’ in Mathematics. Express 18 as a product of its prime factors Split 18 into two smaller factors 18 Solid circle around prime numbers to stop that branch 3 6 2 Split 6 into two smaller factors Solid circle around prime numbers to stop that branch 3 Once every branch has reached a prime number, multiply all the prime numbers together ` 18 = 2 =2 3 # 3 32 # # Simplify answer ALWAYS at the prime number. 3 Don’t ever do this 1 3 because 1 is NOT a prime number Whole Numbers Mathletics Passport © 3P Learning Remember: A prime number has two factors, itself and 1 H 3 SERIES TOPIC 25 Where does it work? Whole Numbers Here are some more examples. Express 38 as a product of its prime factors 38 Split 38 into two smaller factors 19 2 Solid circle around prime numbers to stop that branch Once every branch has reached a prime number, multiply all the prime numbers together ` 38 = 19 # 2 There is often more than one way to create a factor tree for numbers with a lot of factors. Express 48 as a product of its prime factors Split 48 into two smaller factors 48 2 4 Split 6 and 8 into two smaller factors 6 8 3 2 2 2 Solid circle around prime numbers to stop that branch Split 4 into two smaller factors Solid circle around prime numbers to stop that branch Once every branch has reached a prime number, multiply all the prime numbers together ` 48 = 2 # 2 # 2 # 3 # 2 = 24 # 3 26 H 3 SERIES TOPIC Simplify answer Whole Numbers Mathletics Passport © 3P Learning Where does it work? Your Turn Whole Numbers Factor trees Fill in the missing values on the following factor trees and write the number as a product of its primes. 12 b 18 4 2 2 3 ` 12 = c ` 18 = 32 d 56 14 4 2 4 2 2 ` 56 = 2 e 84 f 128 12 ..../... ../20... TREES * ` 32 = OR IME FACT PR TREES * OR a IME FACT PR 1 2 4 2 3 ` 84 = ` 12 8 = Whole Numbers Mathletics Passport © 3P Learning H 3 SERIES TOPIC 27 Where does it work? Your Turn Whole Numbers Factor trees 2 Complete a factor tree for each number below and express them as a product of their prime factors. a 8 b 20 ` 8 = ` 20 = c 24 d ` 24 = e 96 f 28 H 3 SERIES TOPIC ` 60 = ` 96 = ` 144 = Whole Numbers Mathletics Passport 60 © 3P Learning 144 Where does it work? Whole Numbers Highest common factor (HCF) The HCF is the largest number that divides exactly into two or more composite numbers. Write all the factors of each number then circle the largest one which appears in both lists. Find the highest common factor for these pairs of numbers (i) 6 and 8 Factors of 6: 1 , 2 , 3 , 6 List all the factors for each number Factors of 8: 1 , 2 , 4 , 8 Circle the largest number common to both lists ` The HCF for 6 and 8 is: 2 (ii) 18 and 12 Factors of 18: 1 , 2 , 3 , 6 , 9 , 18 List all the factors for each number Factors of 12: 1 , 2 , 3 , 4 , 6 , 12 Circle the largest number common to both lists ` The HCF for 18 and 12 is: 6 We can use the list of prime factors for larger numbers to find the HCF. Find the HCF for these pairs of larger numbers (i) 72 and 96 Factors of 72: 2 , 2 , 2 , 3 , 3 List all the prime factors for each number Factors of 96: 2 , 2 , 2 , 2 , 2 , 3 ` The HCF for 72 and 96 is: 2 # 2 # 2 # 3 = 24 (ii) 528 and 624 Factors of 528: 2 , 2 , 2 , 2 , 3 , 11 Factors of 624: 2 , 2 , 2 , 2 , 3 , 13 ` The HCF for 528 and 624 is: 2 # 2 # 2 # 2 # 3 = 48 List all the prime factors for each number Whole Numbers Mathletics Passport © 3P Learning H 3 SERIES TOPIC 29 Your Turn Highest common factor (HCF) RS * H CTO IG Find the highest common factor for these pairs of numbers. a 8 and 12 b 6 and 15 c 10 and 18 d 18 and 24 e 14 and 28 f 16 and 36 FA HCFs ..../..... /20... O ST C MMO N HE 1 Whole Numbers COMMO ST N HE Where does it work? RS * H CTO IG FA 2 Use the prime factors to find the HCF for these larger numbers. a 42 and 84 b 92 and 72 c 280 and 490 d 256 and 640 30 H 3 SERIES TOPIC Whole Numbers Mathletics Passport © 3P Learning Where does it work? Whole Numbers Lowest common multiple (LCM) The LCM is the smallest number that is common to the multiplication tables of two or more numbers. Write down the multiples of the numbers and stop once you find the lowest common multiple. Find the lowest common multiple for these pairs of numbers (i) 2 and 5 2#2 6#2 Multiples of 2: 2 , 4 , 6 , 8 , 10 , 12 , 14 ,... List some multiples of the first number 1#2 4#2 3#2 7#2 5#2 2#5 Multiples of 5: 5 , 10 ,... List the multiples of the second number until there is a match 1#5 ` The LCM for 2 and 5 is: 10 (ii) 6 and 8 Multiples of 6: 6 , 12 , 18 , 24 , 30 ,... List some multiples of the first number Multiples of 8: 8 , 16 , 24 ,... List the multiples of the second number until there is a match ` The LCM for 6 and 8 is: 24 We can use the list of prime factors for larger numbers to find the LCM by looking at the differences. Find the LCM for these pairs of larger numbers (i) 30 and 100 Prime factors of 30: 2 , 3 , 5 List all the prime factors for both numbers Prime factors of 100: 2 , 2 , 5 , 5 Circle all the different factors in the smaller number ` The LCM for 30 and 100 is: 100 # 3 = 300 Multiply the larger number by the different factor (ii) 24 and 388 Prime factors of 24: 2 , 2 , 2 , 3 List all the prime factors for both numbers Prime factors of 388: 2 , 2 , 97 Circle all the different factors in the smaller number ` The LCM for 15 and 388 is: 388 # 2 # 3 = 2328 Multiply the larger number by the different factors Whole Numbers Mathletics Passport © 3P Learning H 3 SERIES TOPIC 31 Your Turn Lowest common multiple (LCM) Find the lowest common multiple for these pairs of numbers. a 3 and 9 b 5 and 10 c 4 and 6 d 5 and 6 e 6 and 7 f 12 and 16 PLE * L LTI O U M LCM s ..../..... /20... COMMON ST WE 1 Whole Numbers COMMON ST WE Where does it work? IPLE * L LT O MU 2 Use the prime factors to find the LCM for these larger numbers. a 60 and 108 b 42 and 150 c 168 and 180 d 210 and 385 32 H 3 SERIES TOPIC Whole Numbers Mathletics Passport © 3P Learning Whatelse elsecan canyou youdo? do? What Whole Numbers Whole Numbers Pascal’s triangle This amazing triangle developed in 1653 by French mathematician Blaise Pascal uses the addition of two whole numbers to create it. The number pattern forms the shape of a triangle and contains many mathematical applications. To create Pascal’s triangle, each number on the line is obtained by adding the two numbers above it. The first seven lines of Pascal’s Triangle 1 0+1 1+0 1 1 0+1 1+1 1+0 1 2 1 0+1 1+2 2+1 1+0 1 3 3 1 0+1 1+3 3+3 3+1 1+0 1 4 6 4 1 0+1 1+4 4+6 6+4 4+1 1+0 1 5 10 10 5 1 0+1 1+5 5 + 10 10 + 10 10 + 5 5+1 1+0 1 6 15 20 15 6 1 The pattern continues in the same fashion for each added row of numbers The second diagonal of Pascal’s triangle contains all the counting numbers Counting numbers Counting numbers 1 1 1 2 1 3 1 5 1 1 6 3 4 1 1 15 4 6 10 1 5 10 20 1 15 Whole Numbers Mathletics Passport © 3P Learning 1 6 1 H 3 SERIES TOPIC 33 What else can you do? Whole Numbers Here are some more patterns found within Pascal’s triangle. The third diagonal of Pascal’s triangle contains triangular numbers 1 Triangular numbers 1 1 1 1 1 6 3 6 4 10 5 1 2 3 1 15 Triangular numbers 1 1 4 1 10 5 15 20 1 6 1 Triangular numbers are formed by creating equilateral triangles using dot diagrams starting from 1 dot , ,,, ,... 1 36 10 15 A very well known number pattern which occurs frequently in nature is the Fibonacci Sequence. The Fibonacci sequence is also within Pascal’s triangle and is found by adding terms along the lines shown 1 1 1+1= 2 1+2= 3 1+3+1= 5 3+4+1= 8 1 + 6 + 5 + 1 = 13 1 1 1 1 1 1 1 2 3 4 5 6 1 15 1 3 6 10 1 4 10 20 Sunflowers contain a Fibonacci sequence 1 5 15 1 6 1 Each number in a Fibonacci Sequence is found mathematically by adding the two numbers before it 1 34 ,1,2 , 3 ,5,8,13 ,21 ,... 0 + 1 1 + 11 + 22 + 3 3 + 55 + 88 + 13 H 3 SERIES TOPIC Whole Numbers Mathletics Passport © 3P Learning What else can you do? Your Turn Whole Numbers Pascal’s triangle Another special pattern is called the Sierpinkski Triangle. This is a special fractal pattern made using triangles. Each dark equilateral triangle is split into four smaller equilateral triangles at every step. This pattern can be reproduced using Pascal’s triangle by simply separating the odd and even numbers. In Pascal’s triangle below, colour in all the odd numbered hexagons to see this pattern emerge! 1 14641 AL’S TRI SC 1331 1 1 1 2 1 1 ..../... ../20... GLE * PA AN 121 AL’S TRI SC GLE * PA AN 11 15101051 1615201561 1 721353521 7 1 1 82856705628 8 1 1 936841261268436 9 1 1 10 45120210252210120 45 10 1 1 11 55165330462462330165 55140 1 1 12 66220495792924792495220 66 12 1 1 13 782867151287171617161287715286 78 13 1 1 14 91 3641001200230033432300320021001 364 91 14 1 1 15 105 45513653003500564356435500530031365 455 105 15 1 Whole Numbers Mathletics Passport © 3P Learning H 3 SERIES TOPIC 35 What else can you do? Whole Numbers Applications of Pascal’s triangle Pascal’s triangle can often be useful when solving problems like the ones shown here. Each number in Pascal’s triangle represents the number of paths that can be taken to get to that point. Show all the different downward paths that can be taken to get to the circled number in the triangle 1 1 1 1 2 3 1 1 3 1 The number circled is 3, so there are 3 different downward paths leading to this point 1 1 1 1 1 1 2 3 1 1 3 1 1 1 1 1 2 3 1 1 3 1 1 Path 2 Path 1 1 1 2 3 1 3 1 Path 3 The total number of different paths to the bottom of a Pascal triangle is found by adding the numbers across. For this four-line Pascal triangle: (i) How many different paths can be taken to reach the bottom of the triangle below? 1 1 1 1 1 2 3 The total number of different paths = 1 + 3 + 3 + 1 =8 1 3 1 (ii) How many paths to reach the bottom if one more line was added? 1 1 1 1 1 36 1 2 3 4 H 3 SERIES TOPIC 1 3 6 The total number of different paths = 1 + 4 + 6 + 4 + 1 = 16 1 4 1 Whole Numbers Mathletics Passport © 3P Learning What else can you do? Your Turn Whole Numbers Applications of Pascal's triangle 1 Write down how many different downward paths there are to each of the points circled on this triangle. A B C D F E Number of downward pathways to: 2 A = B = C = D = E = F = Show the six different downward paths that lead to the circled point on this triangle from the top. Start 6 Start Start Start Path 1 Path 2 Path 3 Start Start Start Path 4 Path 5 Path 6 Whole Numbers Mathletics Passport © 3P Learning H 3 SERIES TOPIC 37 What else can you do? Your Turn Whole Numbers Applications of Pascal's triangle 3 The ant nest below has a tunnel system that leads down to a main chamber. After one ant enters the tunnel from the top, how many different ways can it get to the main chamber if it only travels downwards the entire way? Hint: Fill in Pascal’s triangle values. Main Chamber 38 H 3 SERIES TOPIC Whole Numbers Mathletics Passport © 3P Learning Rememb er me? Cheat Sheet Whole Numbers M ×1 × 10 × 100 × 1000 × 10 000 × 100 000 Adding and subtracting large numbers When adding or subtracting large numbers, make sure the place values are lined up correctly first. NU MB E R S × 1 000 000 Place value • Writing numbers using words, name using groups of three digits. • To write in expanded form, multiply each number by the place value and add together. • The place value of a numeral in a large number is found by multiplying the numeral by the matching position value. illi o H u ns nd Te red ns s o f o T h f t h t ho ou ou us a s Hu and san nds d nd s s r e Te ns ds On es Here is a summary of the important things to remember for whole numbers. Long multiplication • Make sure the place values are lined up correctly first. • Add zeros on each line to match the place value of the number you are multiplying by. • Add together the new numbers formed after multiplying. Short and long division • Keep all place values lined up neatly. • Be careful and methodical with each step. • Always write the remainder as a fraction. Index notation for numbers Index notation is used to show how many times a number is multiplied by itself. 3 # 3 # 3 # 3 # 3 = 35 Square and cube roots • The square root or cube root of a number is the opposite operation to squaring or cubing. for square root and 3 for cube root. • The symbols used are 9 = 3 because 3 # 3 = 9 and 3 27 = 3 because 3 # 3 # 3 = 27 Factor trees These are used to write any composite number as the product of prime number factors only. Highest common factor (HCF) The HCF is the largest number that divides exactly into two or more composite numbers. Lowest common multiple (LCM) The LCM is the smallest number that is common to the multiplication tables of two or more numbers. Pascal’s triangle • Each number in Pascal’s triangle is the sum of the two numbers above it. • Each number is the number of different downward paths that can be taken to get to that point. • The number of different downward paths to the bottom of a Pascal’s triangle is found by adding together all the values across the bottom. Whole Numbers Mathletics Passport © 3P Learning H 3 SERIES TOPIC 39 Whole Numbers 40 H 3 SERIES TOPIC Notes Whole Numbers Mathletics Passport © 3P Learning ..../..... /20... FOR NU ISIBIL V I S Y TEST IT ERS * D MB LE NUM HO RS * W BE LE NUM HO ..../..... ..../..... /20... LE NUM HO * IND ON NOTAT I * IND ON EX ..../...../20... * WHOLE NOTA T I * WHOLE alue V e c Pla ../20... . EX NUMBERS ..../.. /20... LE NUM HO RS * W BE RS * W BE Short a Divisnido Long n RS * W BE Squ and Caurbe roots e roots NUMB ERS