Estimating Addends

Based on the rules for rounding off numbers, which is the best example of a good estimate for 487 + 36?

• 490 + 40

• 500 + 40

• 500 + 30

• 490 + 30

What are the possible addends if the estimated sum is 500?

• 566 and 122

• 430 and 211

• 352 and 216

• 278 and 189

What is the estimated sum of 427 and 618?

From the choices below, which is the correct estimated sum for 745 and 268?

• 950

• 900

• 1 000

• 1 100

In adding numbers using the split method, what number should be written inside the box?

• 20

• 50

• 30

• 70

Get the estimated sum of 123 and 456.

• 580

• 600

• 500

• 650

In adding numbers mentally, what number should we add to 345 to make it 500?

• 150

• 155

• 100

• 255

• 67

• 47

• 60

• 77

• 18

• 70

• 75

• 100

• 60

• 59

• 55

• 90