Sec 02 - 014-025.qxd 2.1 19/11/03 8:17 am Page 14 Key words Place value digit units tens hundreds thousands place value zero place holder Read and write numbers using digits or words Know the value of each digit in a whole number The position of each digit in a number shows its value: 3 6 7 2 2 units 7 tens 6 hundreds 3 thousands You can use headings to show the place value of each digit: Th 3 H T U 6 7 2 This number can be written in words: Three thousand, six hundred and seventy two 3672 is a 4-digit number Example 1 What is the value of the underlined digit in the following numbers: a) 95 b) 6307 a) 90 9 tens b) 300 3 hundreds c) 5 Example 2 c) 125 5 units Write 8 300 5000: a) as a single number b) in words There are no tens. The 0 in the tens column is called a zero place holder. a) 5308 b) Five thousand, three hundred and eight Example 3 What is the value of each position on this number line? (c) (a) 4000 a) 4320 14 b) 4750 Maths Connect 1G (e) (b) 4500 c) 4140 d) 4890 (d) 5000 e) 4640 The large divisions mark hundreds. The small divisions mark tens. Sec 02 - 014-025.qxd 19/11/03 8:17 am Page 15 Exercise 2.1 What is the value of the underlined digit in the following numbers: a) 64 b) 435 c) 2917 d) 7832 e) 5420 e) 3117 Write these numbers using digits: a) b) c) d) e) f) Ninety five Six hundred and eighty seven Four thousand, three hundred and twenty six Five thousand, one hundred and eight Seven thousand and twenty three Twenty six thousand, three hundred and forty one You need to use a zero place holder for parts d) and e). Write these numbers in words: a) 35 b) 267 c) 4591 d) 3605 e) 27 346 For each of a), b) and c), put these place value cards together to create one number and write down that number: a) 6 0 b) 0 0 7 5 3 0 c) 0 8 6 4 0 7 0 0 0 0 5 0 Write each of the following as a single number: a) 400 50 8 d) 70 4000 5 0 8 0 b) 2000 100 60 7 e) 200 7 6000 c) 500 9 3000 20 f) 25 000 40 600 9 What is the value of each position on these number lines: (a) 300 (f ) (b) (c) (g) (d) (h) (e) (i) (j) 5000 400 6000 Write out the following: a) 100 more than 456 d) £1000 less than £4479 b) 10 less than 6582 e) 10 kg more than 1690 kg c) 1 more than 4508 f) 10 m less than 3200 m Investigation You need these four digit cards: Investigate how many 4-digit numbers you can make which are greater than 7000. 5 2 7 4 You could start with numbers beginning with 72 , then 74 , then 75 How many 4-digit numbers can you make which are less than 5000? Place value 15 Sec 02 - 014-025.qxd 2.2 19/11/03 8:17 am Page 16 Key words Tenths tenth decimal number decimal point Understand the meaning of a tenth Write tenths as fractions and decimals When a unit is divided into ten equal parts, each part is called a tenth . one tenth 5 6 You can write tenths using decimal numbers . A decimal point separates the whole numbers from the tenths: 13 . 7 1 ten 3 units decimal point A decimal number is sometimes just called a decimal. 7 tenths or 170 You can show this on a number line or using place value headings: 13.7 13 Example 1 7 10 b) 0.7 Example 2 tenths column Write the shaded part of this shape as: a) a fraction a) TU . t 1 3 . 7 14 b) a decimal The shape is divided into 10 equal parts. Each part is one tenth. 7 parts are shaded. What is the value of each position on this number line: (a) (b) (c) (d) (e) 6 units and 4 tenths. 6 a) 6.4 7 b) 6.9 c) 7.0 or 7 8 d) 7.4 e) 7.7 7 units and 0 tenths. You can write 7.0 or 7 Example 3 Write ‘two units and one tenth’ as a) a fraction b) a decimal. 1 a) 210 16 Maths Connect 1G b) 2.1 Sec 02 - 014-025.qxd 19/11/03 8:17 am Page 17 Exercise 2.2 Write the shaded part of each shape as: i) a fraction a) b) c) Write these fractions as decimal numbers: a) 3 10 b) ii) a decimal 7 10 c) 1120 d) d) 2110 e) 3150 d) 11.7 e) 2.5 Write these decimal numbers as fractions: a) 0.1 b) 0.9 c) 3.6 Write each number as: i) a fraction a) b) c) d) ii) a decimal Look at Example 3. six tenths four units and nine tenths two hundreds, eight tens, one unit and five tenths three tens and one tenth What is the value of each position on these number lines: (a) (b) (c) (d) (e) (i) (j) 2 3 (f ) (g) 3 (h) 4 5 Write each of the following answers as a decimal: a) 70 3 0.2 b) 0.5 60 4 c) 7 0.2 20 Write these numbers as decimals: a) 110 more than 5.3 d) 1 less than 8.5 g) 0.1 more than 15.6 b) 110 less than 6.5 e) 0.1 more than 15.6 h) 0.1 less than 7 c) 1 more than 2.7 f) 0.1 less than 2.9 What needs to be added or subtracted to change 17.8 to: a) 17.9 b) 18.8 c) 7.8 d) 17.7 e) 27.9? Who am I? I am a decimal number. I am between 3 and 4. My digits add up to 8. Investigation You need a counter to use as a decimal point and these 3 digit cards: 3 5 6 a) How many decimal numbers You could start with numbers beginning with 6 tenths . 6, can you make of the form .? then 5 tenths . 5 and so on. b) Write the numbers, in order, from smallest to largest. c) How many of them are more than 50? d) How many are between 30 and 40? Tenths 17 Sec 02 - 014-025.qxd 2.3 19/11/03 8:17 am Page 18 Key words Hundredths tenth hundredth decimal Understand the meaning of a hundredth Write tenths and hundredths as fractions and as decimals When a unit is divided into one hundred equal parts, each part is called a hundredth . There are ten hundredths in one tenth . 5 5.1 5.2 5.3 5.4 5.5 one tenth 5.6 5.7 5.8 6 5.9 one hundredth You can write hundredths using decimals : 25.69 2 tens 5 units 6 tenths or 160 9 hundredths or 1900 You can show this on a number line or using place value headings: 25.69 25.6 Example 1 hundredths column What is the value of the underlined digit in the following numbers: a) 3.87 b) 25.49 a) 7 hundredths b) 4 tenths c) 6 units d) 8 tens Example 2 TU . t h 2 5 . 6 9 25.7 c) 6.73 d) 183.19 H T 2 1 8 U 3 5 6 3 . . . . . t 8 4 7 1 h 7 9 3 9 Write the following as decimals: a) Four units, nine tenths and six hundredths b) 60 130 1400 a) 4.96 Example 3 c) 8 0.1 0.07 b) 60.34 60 130 1400 60 0.3 0.04 c) 8.17 Work out the value of £0.10 more than £5.81. £5.81 £0.10 £5.91 Add one tenth to the eight tenths Exercise 2.3 What is the value of the underlined digit in the following numbers: a) 4.25 b) 17.36 c) 3.78 d) 5.38 e) 145.06 f) 7.01 g) 2107.44 h) 322.59 i) 17.08 j) 0.09 18 Maths Connect 1G Sec 02 - 014-025.qxd 19/11/03 8:17 am Page 19 Write the following as decimals: a) Five units, nine tenths and three hundredths b) Four tens, seven units, one tenth and six hundredths c) Nine hundreds, three units, two tenths and six hundredths d) One unit and one hundredth Write the following as decimals: a) 7 0.8 0.02 b) 0.3 10 0.05 6 d) 0.04 0.6 30 e) 1700 130 9 g) 2000 6 1800 190 h) 1400 3 c) 5 0.09 20 f) 10 1500 110 Write these fractions as decimal numbers: a) 12030 b) 14050 c) 111070 d) 21700 What is the value of each position on these number lines: (a) 10 hundredths 1 tenth 100 hundredths 1 unit (b) (c) (d) (e) 2 3 (f ) (g) (h) (i) 10 (j) 11 Work out the following: 1 a) 100 more than 4.72 d) 0.01 less than 4 b) 1 less than 5.59 e) 0.1 more than 5.68 Work out the value of: a) £1.00 less than £4.71 c) £0.10 less than £0.89 e) £0.01 less than £12.60 b) £0.10 more than £1.50 d) £0.01 more than £2.99 f) £0.10 more than £5.95 What needs to be added or subtracted to change 3.67 to: a) 3.68 b) 3.57 c) 4.67 d) 3.69 c) 0.01 more than 6.36 f) 0.1 less than 5.07 Look at Example 3. e) 2.66? Jamie has collected fifteen £1 coins, seven 10p coins, and eight 1p coins. Write how much he has left after spending £0.42. The builders are building a wall that is 1.32 metres long at the moment. After working on it the next day it is 4 tenths of a metre longer, and the day after it is 14060 of a metre longer still. How long is the wall now? Investigation You need a counter to use as a decimal point and these four digit cards: 8 7 4 2 a) What is the biggest number you can make? b) What is the smallest number you can make of the form . ? c) How many of numbers can you make between 50 and 100? Hundredths 19 Sec 02 - 014-025.qxd 2.4 19/11/03 8:17 am Page 20 Key words Multiplying and dividing by 10, 100 and 1000 multiply divide convert place value grid Know how to multiply numbers by 10, 100 and 1000 Know how to divide numbers by 10, 100 and 1000 To multiply a number by 10, 100 or 1000 you move the digits one, two or three places to the left on a place value grid . To divide a number by 10, 100 or 1000 you move the digits one, two or three places to the right on a place value grid. Th H T U . t 9 . 3 5 9 3 . 5 9 3 5 7010 100 3 5 0 7010 1000 9.35 10 9.35 100 9.35 1000 Example 1 9 a) 59 10 590 b) 166 100 T U 7 0 1 0 7 0 1 7 7010 10 c) 3.8 100 b) 166 100 1.66 Find in each of the following: a) 870 8.7 a) 870 100 8.7 Example 3 Th H Work out: a) 59 10 Example 2 h c) 3.8 100 380 b) 35 350 b) 35 10 350 . t h 0 . 1 7 . 0 1 The digits move one place to the left. You need to add a zero place holder. c) 4.1 4100 c) 4.1 1000 4100 To get from 870 to 8.7 you move two places to the right on a place value grid. Convert 42 m into cm. 42 100 420 1 m 100 cm. To convert m into cm multiply by 100. Exercise 2.4 Copy and complete this place value grid: Th H 67 10 67 100 67 10 67 100 20 Maths Connect 1G 6 T U 6 7 . t h Sec 02 - 014-025.qxd 19/11/03 8:17 am Page 21 Work out: a) 7 10 b) 43 10 c) 152 100 d) 95 100 e) 5.6 100 f) 31.1 10 g) 1.7 1000 h) 3.8 100 i) 9180 1000 j) 0.03 1000 Find in each of the following: a) 76 7600 d) 4.7 4700 c) 85 8.5 h) 147 14.7 i) e) 6.49 64.9 g) 1475 14 750 j) b) 1500 15 1000 4610 f) 372 3.72 10 37.1 Find the matching letter from the box for the answer to each of the following: a) 32 10 b) 32 10 c) 320 10 d) 0.32 100 e) 3200 10 f) 3.2 100 g) 320 1000 h) 0.32 1000 i) 3200 100 j) 100 3.2 A 32 B 3.2 C 0.32 D 320 Convert: a) 600 cm into m b) 80 cm into mm c) 350 m into cm d) 75 mm into cm e) 0.5 m into cm f) 3.5 m into mm 100 cm 1 m 10 mm 1 cm Write these amounts in pounds: a) 356p b) 470p c) 24p d) 60p e) 2800p f) 1385p Write these amounts in pence: a) £1.50 b) £4 c) £3.26 d) £6.40 e) £7.05 f) £16 Work out: a) 3 10 10 b) 47 100 10 c) 5600 10 10 d) 2.3 100 10 e) 100 10 3.4 f) 470 100 10 The Seashore Store buys 100 buckets at £2.52 each, and then sells them at £3 each. How much profit has it made? Investigation Use the digits 2 and 4, and as many zeros as you like, together with any of these operations: 1 1 10 10 100 100 Can you write eight different true statements like this: 24 100 24 10 1000 1000 You could try statements that contain two signs, then two signs, then one of each sign. Multiplying and dividing by 10, 100 and 1000 21 Sec 02 - 014-025.qxd 2.5 19/11/03 8:17 am Page 22 Key words Positive and negative numbers positive number negative number integer Recognise positive and negative numbers Know how to put positive and negative numbers in order You can count back past zero on a number line:` The numbers below zero are called negative numbers . You write The numbers above zero are called positive numbers . You can write negative numbers with a sign in front of them. positive numbers with a sign in front of them. 5 4 3 2 1 1 0 2 3 4 5 The set of positive and negative whole numbers, including zero, are called integers . This temperature scale shows positive and negative temperatures: Vienna Palma Barbados Seoul London Orlando ⴚ10 ⴙ10 0 ⴙ20 ⴙ30°C Thermometer Example 1 The temperature in Seoul is 6 °C. This is 6 °C below zero. Write down the next four numbers in the sequence 10, 7, 4, … –10 –9 –8 –7 –6 –5 –4 –3 –2 –1 The temperature in Orlando is 19 °C. This is 19 °C above zero. 0 +1 +2 +3 +4 +5 +6 +7 +8 +9 +10 Counting back in threes. 1, 2, 5, 8 Example 2 –5 Write these numbers in order, smallest first: 5, 1, 3, 4, 2 –3 –5 + 1 +2 0 Marking the numbers on a number line. +4 +5 The order is: 5, 3, 1, 2, 4 Example 3 Decide whether the temperature has risen or fallen, and by how much: (b) ⴚ10 0 (a) ⴙ10 a) from 9 °C to 4 °C b) from 4 °C to 3 °C 22 Maths Connect 1G a) Fallen by 5 °C b) Risen by 7 °C ⴙ20 °C Sec 02 - 014-025.qxd 19/11/03 8:17 am Page 23 Exercise 2.5 Write down the next five numbers in each sequence: a) 10, 8, 6, 4, … b) 25, 20, 15, 10, … c) 7, 5, 3, … d) 8, 6, 4, … Positive numbers are sometimes written without the sign. 10 is the same as 10. What is the value of each position on this number line: (c) (e) (a) 10 (d) (b) (f ) 10 0 Draw a number line from 5 to 5. Label the positions of these points on the line. a) 2 b) 4 c) 312 d) 2.5 e) 0.5 Write the temperatures in each cloud in order, lowest first: a) c) e) b) 3°C, 2°C, 1°C, 4°C, 1°C d) 0°C, 4°C, 1°C, 3°C, 2°C f) 5°C, 1°C, 2°C, 6°C, 3°C 5°C, 3°C, 6°C, 2°C, 0°C 6°C, 6°C, 3°C, 3°C, 1°C 0°C, 2°C, 1°C, 1°C, 2°C Write ‘True’ or ‘False’ for each statement: b) 2 is more than 6 a) 3 is less than 4 c) 5 is more than 2 d) 3 is less than 1 e) 3 is more than 7 f) 4 is less than 6 Use a number line to help you. Write each pair of numbers, with either a or sign between them. a) 2 and 4 b) 3 and 5 c) 3 and 5 d) 3 and 2 e) 5 and 1 f) 1 and 3 g) 0 and 5 h) 4 and 0 i) 6 and 2 means ‘less than’ means ‘more than Decide if the temperature has risen or fallen, and by how much: a) from 11 °C to 2 °C b) from 5 °C to 4 °C c) from 9 °C to 3 °C d) from 2 °C to 1 °C e) from 4 °C to 15 °C f) from 1 °C to 9 °C Work out the following: a) 5 more than 2 b) 3 less than 2 c) 6 less than 7 d) 4 less than 1 The temperature is shown on this thermometer. ⴚ10 0 ⴙ10 ⴙ20 °C What would the temperature be after the following changes: a) rises by 3 °C b) falls by 2 °C c) falls by 8 °C d) rises by 6 °C e) rises by 7 °C, and then falls by 4 °C The temperature in Shipton is 6 °C at midday. It decreases by 2 degreees every hour for the next five hours. What is the temperature at 5 o’clock in the afternoon? Positive and negative numbers 23 Sec 02 - 014-025.qxd 2.6 19/11/03 8:17 am Page 24 Key words Adding add carry Add whole numbers using written methods Estimate answers to addition by rounding You can add whole numbers using a pencil and paper in two different ways. Always start with an estimate. To use the long method you add the units, tens, hundreds and thousands separately: To calculate 4573 1652: Estimate 6000 4573 + 1652 32 5 70 50 120 500 600 1100 4000 1000 5000 6225 4573 + 1652 4000 1000 5000 500 600 1100 70 50 120 32 5 6225 You can start with the units or with the thousands. Always write your numbers in the correct place value column. To use the short method you can start adding from the right. If a column adds up to 10 or more you carry the tens into the next column on the left: 4573 + 1652 6225 7 5 12, so you need to carry 1 into the next column. 11 Example 1 Work out 3906 2291 using the long method. You can add the units first, then the tens, then the hundreds, then the thousands. 3906 229 1 7 90 1 1 00 5000 6 1 97 Example 2 Work out 2867 673 3685 using the short method. 2867 673 3685 7225 22 1 24 Maths Connect 1G Estimate 7000. 7 3 5 15, so you need to carry 1 ten into the next column. Sec 02 - 014-025.qxd 19/11/03 8:17 am Page 25 Exercise 2.6 Work out: a) 472 356 c) 226 702 441 e) 810 758 365 g) 268 391 654 b) d) f) h) Work out: a) 1007 3691 4010 d) 8216 3170 15 g) 2795 1368 2895 b) 456 3724 e) 9306 2997 h) 812 3625 7085 973 c) 5846 326 f) 5407 3062 1793 i) 7584 2648 584 1309 Copy and complete these addition pyramids. a) The number in each brick is found by adding the two directly below it. b) 45 731 25 You can use either the long method or the short method. 685 249 907 366 837 546 792 137 238 456 732 439 854 176 398 235 This electrical store is having a sale. SALE Calculate the cost of: a) a computer and a stereo b) a DVD player and a video camera c) a widescreen TV and a computer d) a video camera, a computer and a stereo e) two computers and a DVD player f) one of each item. Computer Widescreen TV Stereo Video Camera DVD Player This is the map of a fun run. START The run has been divided into four stages. a) How long is the whole run? b) How far will I have run if I stop after Stage 3? £1576 £764 £1236 £859 £685 Stage 1: 2709 m Stage 2: 2920 m Stage 3: 875 m FIN IS H Stage 4: 1088 m Investigation You need digit cards from 0 to 9. Use the cards to create correct additions: For example, 5 7 1 This arrangement creates a 4-card addition. 2 2 7 8 3 5 This arrangement creates a 5-card addition. Can you create a 6-card addition, 7-card addition, and so on … Adding 25