Estimate Sums and Differences

Front

What is the process of estimating sums and differences in mathematics?

Back

Estimating sums and differences involves rounding numbers to a specific place value (such as nearest ten, hundred, or thousand) to simplify calculations and make them easier to perform mentally.

Front

How do you round a number to the nearest hundred?

Back

To round a number to the nearest hundred, look at the digit in the tens place. If it is 5 or greater, round up; if it is 4 or less, round down.

Front

Estimate the sum of 327 and 431 by rounding to the nearest hundred.

Back

700

Front

What is the estimated sum of 56 and 79?

Back

140

Front

How do you estimate the difference of two numbers?

Back

To estimate the difference, round each number to the nearest specified place value and then subtract the rounded numbers.

Front

Estimate the difference of 7,900 and 2,999 by rounding to the nearest thousand.

Back

5,000

Front

What is the best estimate for the total number of items if Tracy ordered 325 pet toys and 165 bags of dog food?

Back

500

Front

How do you find the total number of items ordered by rounding?

Back

Round each quantity to the nearest ten or hundred, then add the rounded numbers together.

Front

A museum has 237, 349, and 219 works of art on three floors. How do you estimate the total number of works of art?

Back

Round each number to the nearest hundred: 200 + 300 + 200 = 700.

Front

What is the importance of using the greatest place value when estimating totals?

Back

Using the greatest place value helps simplify calculations and provides a quick approximation of the total.