Estimating Decimal Sums and Rounding

In this video, Mr. J explains how to estimate decimal sums by rounding each decimal to the nearest whole number and then adding them. The video includes four examples demonstrating this process. Each example shows the rounding of decimals to the nearest whole number, the addition of these rounded numbers, and a comparison of the estimated sum to the exact sum. The video aims to help viewers understand how to find approximate values for decimal sums through estimation.

What is the first step in estimating decimal sums?

• Multiply the decimals.

• Add the decimals directly.

• Round each decimal to the nearest whole number.

• Subtract the smaller decimal from the larger one.

When rounding 7.7 to the nearest whole number, what do you get?

• 7

• 6

• 9

• 8

What is the estimated sum of 7.7 and 2.9 when rounded to the nearest whole number?

• 11

• 10

• 13

• 12

What whole number does 5.2 round to?

• 4

• 7

• 5

• 6

What is the estimated sum of 5.2 and 3.39 when rounded to the nearest whole number?

• 9

• 8

• 10

• 7

To what whole number does 11.99 round?

• 10

• 11

• 12

• 13

What is the estimated sum of 11.99 and 4.15 when rounded to the nearest whole number?

• 16

• 15

• 18

• 17

What whole number does 3.093 round to?

• 5

• 4

• 3

• 2

What is the estimated sum of 3.093 and 2.789 when rounded to the nearest whole number?

• 5

• 6

• 7

• 8

What is the purpose of estimating decimal sums?

• To make calculations more complex.

• To find the exact answer.

• To avoid using decimals.

• To get an approximate value close to the exact answer.