Summary 75 Section 1.4 Rounding and Estimating Key Concepts To round a number, follow these steps. Step 1 Identify the digit one position to the right of the given place value. Step 2 If the digit in step 1 is a 5 or greater, then add 1 to the digit in the given place value. If the digit in step 1 is less than 5, leave the given place value unchanged. Step 3 Replace each digit to the right of the given place value by 0. Use rounding to estimate sums and differences. Examples Example 1 Round each number to the indicated place. a. 4942; hundreds place 4900 b. 3712; thousands place 4000 c. 135; tens place 140 d. 199; tens place 200 Example 2 Round to the thousands place to estimate the sum: 3929 2528 5452. 4000 3000 5000 12,000 The sum is approximately 12,000. Section 1.5 Multiplication of Whole Numbers and Area Key Concepts Multiplication is repeated addition. The product is the result of multiplying factors. Examples Example 1 16 16 16 16 4 16 64 Example 2 For 3 13 2 78 the factors are 3, 13, and 2, and the product is 78. Properties of Multiplication 1. Commutative Property of Multiplication: Changing the order of the factors does not affect the product. 2. Associative Property of Multiplication:The manner in which the factors are grouped does not affect the product. 3. Multipliction Property of 0:The product of any number and 0 is 0. 4. Multiplication Property of 1:The product of any number and 1 is that number. 5. Distributive Property of Multiplication over Addition:The product of a number and a sum can be found by multiplying the number by each addend. Example 3 1. 2. 3. 4. 4 7 7 4 6 15 72 16 52 7 43 0 0 290 1 290 5. 5 14 82 15 42 15 82
miller_prealgebra_2e_ch1_3
To see the actual publication please follow the link above