Estimate sums and differences

Estimate sums and differences

Estimate Sums

• First, round each addend to an easier number

• Then, add

Multiple Choice

Estimate the sum of 327+431 by rounding to the nearest hundreds

• 700
• 600
• 758
• 800

Multiple Choice

Estimate the sum of 327+431 by rounding to the nearest hundreds

• 700
• 600
• 758
• 800

Multiple Choice

Estimate the sum of 120+190 by rounding to the nearest hundreds

• 100
• 200
• 0
• 300

Multiple Choice

Estimate the sum of 52+59 by rounding to the nearest tens

• 110
• 100
• 111
• 90

Multiple Choice

Estimate the sum of 37+99 by rounding to the nearest tens

• 120
• 150
• 140
• 136

Estimate differences

• First, round the minuend and subtrahend to make subtraction easier

• Then, subtract

Multiple Choice

Round to the nearest hundred, then estimate:

642 − 137

• 600

• 780

• 500

• 510

Multiple Choice

Estimate the difference to

89-31=

• 70

• 60

• 50

Multiple Choice

Estimate the difference to

71-37=

• 30

• 40

• 35

Now let's try it with decimals...

Fill in the Blanks

Estimate the sum by rounding each number to the nearest whole number and then adding.

8.598 + 2.78

The sum is approximately

Fill in the Blanks

Estimate the sum by rounding each number to the nearest whole number and then adding.

10.17 + 5.13 + 2.6

The sum is approximately

Fill in the Blanks

Estimate the difference by rounding each number to the nearest whole number and then subtracting.

7.096 − 4.774

The difference is approximately

Fill in the Blanks

Estimate the difference by rounding each number to the nearest whole number and then subtracting.

10.477 − 3.316

The difference is approximately

Fill in the Blanks

Estimate the difference by rounding each number to the nearest whole number and then subtracting.

5.104 − 1.972

The difference is approximately

Fill in the Blanks

Estimate the difference by rounding each number to the nearest whole number and then subtracting.

7.4 − 3.7

The difference is approximately

Fill in the Blanks

Estimate the sum by rounding each number to the nearest whole number and then adding.

6.17 + 4.7

The sum is approximately

Fill in the Blanks

Estimate the sum by rounding each number to the nearest whole number and then adding.

7.114 + 6.122

The sum is approximately