Addition and Subtraction

Front

What is addition?

Back

Addition is the process of finding the total or sum by combining two or more numbers.

Front

What is subtraction?

Back

Subtraction is the process of finding the difference between two numbers by taking one number away from another.

Front

What does it mean to estimate?

Back

Estimating means to find an approximate value or answer, often by rounding numbers.

Front

How do you round a number to the nearest hundred?

Back

To round to the nearest hundred, look at the tens digit. If it is 5 or more, round up. If it is 4 or less, round down.

Front

How do you round a number to the nearest ten?

Back

To round to the nearest ten, look at the ones digit. If it is 5 or more, round up. If it is 4 or less, round down.

Front

What is the estimated difference of 470 - 289 when rounded to the nearest hundred?

Back

200

Front

What is the estimated difference of 756 - 549 when rounded to the nearest hundred?

Back

300

Front

What is the estimated difference of 488 - 351 when rounded to the nearest ten?

Back

140

Front

If there are 237 fifth graders and 346 fourth graders, how do you find out how many more fourth graders there are?

Back

Subtract the number of fifth graders from the number of fourth graders: 346 - 237 = 109, which is approximately 100 more.

Front

What is the estimated difference of 786 - 245 when rounded to the nearest ten?

Back

540