Estimating Sums & Differences

Front

What is estimating in math?

Back

Estimating is finding a number that is close enough to the exact answer, often by rounding numbers.

Front

What does it mean to round to the nearest ten?

Back

Rounding to the nearest ten means adjusting a number to the closest multiple of ten.

Front

Estimate the sum of 42 + 59 by rounding to the nearest ten.

Back

90

Front

What is the purpose of estimating sums and differences?

Back

Estimating helps to quickly find an approximate answer without calculating the exact value.

Front

How do you estimate the difference between two numbers?

Back

Round each number to a convenient value, then subtract the rounded numbers.

Front

Estimate how many more fourth graders were on a field trip than fifth graders if there were 237 fifth graders and 346 fourth graders.

Back

100 more

Front

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

Back

500

Front

To the nearest ten, how many more seeds did Brita and her mom count than Max and his dad if they counted 243 and 333 seeds respectively?

Back

90

Front

What is the first step in estimating a difference?

Back

Round each number to the nearest hundred or ten.

Front

Round 642 to the nearest hundred.

Back

600