Basic Number Properties (LMU) There are three basic properties of numbers, and every math problem you have ever worked has obeyed these properties. Although these properties may seem simple and of no importance, the ISEE requires you to be familiar with them to be successful. Exercise 1 Can you describe the three basic properties of numbers? 1. Associative Property 2. Commutative Property 3. Distributive Property 176 Math Skills Basic Number Properties Activity In the following activity, select the response that best illustrates numbers and operations. 1. Which of the following expressions is an example of the distributive property? (A) (B) (C) (D) 2. Associative Property Commutative Property Distributive Property Identity Property Which expression represents the associative property? (A) (B) (C) (D) 6. (10 + 4) × 6 = 6 × (10 + 4) (10 + 6) × 4 = (10 + 4) × 6 (6 × 10) + (6 × 4) = 6 × (10 + 4) (6 × 10) × (6 × 4) = (6 × 10) + 4 The expression 10 × (12 + 15) = 10 × (15 + 12) is an example of which of the following properties? (A) (B) (C) (D) 5. Associative Property Commutative Property Distributive Property Identity Property Which expression represents the commutative property? (A) (B) (C) (D) 4. If you are having trouble with fractions and decimals, try estimating. The expression 4 × 36 = 36 × 4 demonstrates which of the following properties? (A) (B) (C) (D) 3. (32 × 4) + 7 = (32 + 7) × (4 + 7) (32 + 7) × 4 = 4 × (32 + 7) (4 × 32) + (4 × 7) = 4 × (32 + 7) (4 × 32) × (4 × 7) = 4 × 32 × 7 (18 + 2) + 15 = 18 + (15 + 2) (15 + 2) + 18 = (2 + 15) +18 (18 × 15) + (18 × 2) = 18 × (15 + 2) (18 + 15) + (18 + 2) = (18 + 2) + (18 + 15) The expression 2(4y + 3) = 8y + 6 is an example of which of the following properties? (A) (B) (C) (D) Associative Property Commutative Property Distributive Property Identity Property Math Skills 177 Fractions & Decimals (LMU) Operations with fractions and decimals can be troublesome on the ISEE because it is easy to make mistakes, especially if you are in a hurry. Being familiar with common fraction and decimal equivalents will go a long way Exercise 2 Can you give the decimal equivalent to the following fractions? 1. 1 2 5. 1 6 2. 1 3 6. 1 8 3. 1 4 7. 1 9 4. 1 5 8. 1 10 Exercise 3 Can you give the decimal equivalent to the following fractions? 1. 0.2 5. 0.6 2. 0.3 6. 0.7 3. 0.375 7. 0.75 4. 0.4 8. 0.8 Exercise 4 Can you describe the steps for the following operations? 1. Adding two fractions 2. Subtracting two fractions 3. Multiplying two fractions 4. Dividing two fractions 5. Adding with decimals 6. Subtracting with decimals 7. Multiplying with decimals 8. Dividing with decimals 178 Math Skills Fractions & Decimals Activity In the following activity, select the response that best illustrates the correct operation with fractions and decimals. 1. Which of the following is equivalent 1 2 to 2 + 3 ? (A) (B) (C) (D) 2. 3. What is the value of the 3 3 7 expression 8 + 4 – 8 + (B) (C) (D) 4. 1 3 3 5 7 6 8 5 Shelly has 2 3 of a container of 1 3 bake a cake, what portion of the (A) (B) Which of the following is equivalent to 0.75 × 0.5? (A) 0.375 (B) 0.600 (C) 0.850 (D) 1.200 (A) 5. 1 2 ? 1 8 3 8 1 4 3 4 (C) (D) 6. Steven is performing in the Paper Olympics Paper Cutting Extravaganza. He begins by 1 cutting off 3 of his standard sheet of notebook paper. Then, he cuts 1 off 5 of the remaining portion. After the second cut, what fraction of his paper remains? (A) (B) 3 5 A soda bottle is currently full. If Bill drinks half of this amount, what 4 9 1 2 2 3 5 6 (C) (D) 1 15 7 15 8 15 2 3 with soda? (A) (B) (C) (D) 1 5 3 10 2 5 7 10 Math Skills 179 Mixed Numbers (LMU) Mixed numbers appear in many problems. These numbers contain an integer followed by a proper fraction. Before trying to solve problems that contain mixed numbers, it is best to convert the mixed numbers into improper fractions. Exercise 5 Can you convert the following mixed numbers into improper fractions? 1. 1 23 4. 5 61 2. 3 45 5. 6 37 3. 4 29 6. 2 121 Exercise 6 Can you convert the following improper fractions into mixed numbers. 1. 2. 3. 180 Math Skills 5 2 10 3 9 4 4. 5. 6. 17 5 23 6 19 7 Mixed Numbers Activity In the following activity, select the response that best illustrates the correct operation with fractions and decimals. 1. Which of the following is equivalent to the sum of (A) (B) (C) (D) 2. (B) (C) (D) 3. 5 56 6 6 Remember: Operations with mixed numbers can be tough. When you are strapped for time, ESTIMATE! 1 6 5 6 3 45 # 2 13 ? 5 12 6 152 8 13 15 10 38 1 1 Sean has 5 2 slices of pizza. A day later, he only has 3 of his pizza remaining. How many slices of pizza does he have left? (A) (B) (C) (D) 4. 5 15 Which of the following is equivalent to (A) 2 13 and 3 12 ? 1 56 2 13 3 23 4 16 Which of the following is equivalent to (A) (B) (C) (D) 1 2 _ 4 13 + 2 14 i ? 3 247 4 125 5 11 24 6 127 Math Skills 181 5. Which of the following is equivalent to (A) (B) (C) (D) 182 Math Skills 1 12 2 185 4 121 5 16 5 18 ' 2 14 ?