1) The document provides examples and instructions for estimating sums, differences, products, and quotients with whole numbers by rounding to place values. 2) It demonstrates estimating the total distance traveled by rounding numbers to the nearest ten before adding and estimating apples left by rounding to the nearest ten before subtracting. 3) For products, it advises rounding both numbers to the place value of their leading digits before multiplying and uses rounding the divisor to its leading digit as an example of estimating quotients.

1. Chapter 1.2 Whole Number Estimation McDougal Littell Middle School Math Course 1 Joseph Williams Melvin E. Sine Elementary [email_address] Objective : Round to estimate with whole numbers.

2. Vocabulary Leading Digit – p. 13 – the leading digit of a whole number is the first digit at the left. Compatible Numbers – p. 13 – numbers that are easy to use in computations.

3. Estimating Sums To estimate, round each number to the same place value. Then add. 28 + 114 Round each number to the nearest ten. 30 + 110

4. Estimating Sums Your mother drove you 12 miles to the skate park, then 8 miles to the store. After that you drove 6 miles back home. What is an estimate of the total distance you traveled? 12 8 + 6 Round each number. 10 10 + 5 Did you get 25?

5. Estimating Differences To estimate, round each number to the same place value. Then subtract. 208 - 114 Round each number to the nearest hundred. 200 - 100 100

6. Estimating Differences You pick 92 apples. You give your cousin 48 apples. About how many apples do you have left? 92 - 48 Round each number to the nearest ten. 90 - 50 Did you get 40?

7. Estimating Products When you round to estimate a product, you should round the numbers to the place value of their leading digits. 191 x 11 2 00 x 1 0 = 2,000 Round both numbers to the leading digit.

8. Estimating Quotients 469 ÷ 59 469 ÷ 59 469 ÷ 60 Round the divisor to its leading digit. 469 ÷ 60 480 ÷ 60 Replace the dividend With a number compatible With 60 and close to 469.

9. Estimating Quotients Your grandfather gives you 972 pennies. You split them up between you and your 3 brothers. (4 of you altogether) About how many pennies should each of your have? 972 ÷ 4 1,000 ÷ 4 Did you get 250?