Estimating Sums with Benchmarks

Estimating Sums with Benchmarks

Learn how to estimate sums using benchmarks and improve your mathematical skills.

Estimating Sums with Benchmarks

• Today we will learn about a Getting Close game, which is a game that sharpens estimating skills using benchmarks.

• Benchmarks are reference numbers used to estimate the size of other numbers.

Multiple Choice

Which fraction benchmark is 3/8 closest to?

• 1/4

• 1/2

• 3/4

• halfway between 1/4 and 1/2

Raul says that 3/8 is exactly halfway between 1/4 and 1/2. He reasons that 3/8 is less than 1/2 because it is less than 4/8. However, 3/8 is greater than 1/4 because it is greater than 2/8.

Which benchmark is closet to 3/8?

Multiple Choice

Which benchmark is 0.58 closest to?

• 0.5

• 1

• 0

• 1.5

Which benchmark is 0.58 closest to?

Desiree says that since 1/2 is equal to 0.50, 0.58 is greater than 1/2. Also, 0.58 is less than 0.75, which equals 3/4. So, 0.58 is between 1/2 and 3/4, but it is closer to 1/2.

Multiple Select

Cetera wonders if she can use benchmarks to estimate the sum of two fractions, such as the sum below.

1/2 + 5/8

• • between 0 and 1

• • between 1 and 2

• • closest to 0

• • closest to 1

• • closest to 2

Multiple Choice

What is Getting Close?

• A game that sharpens estimating skills using benchmarks

• A game that teaches multiplication tables

• A game that teaches spelling

• A game that teaches coding

Multiple Choice

Suppose you played Getting Close with only these game cards:

Which two cards have the greatest sum?

• 5/6 and 2/3

• 5/6 and 9/10

• 9/10 and 4/5

• 4/5 and 5/6

Multiple Choice

Suppose you played Getting Close with only these game cards:

Which two cards have the least sum?

• 5/6 and 2/3

• 2/3 and 4/5

• 2/3 and 1/2

• 9/10 and 4/5

Multiple Choice

Suppose you played Getting Close with only these game cards:

Estimate the greatest sum.

• 1

• close to 1

• 2

• close to 2

Multiple Choice

Suppose you played Getting Close with only these game cards:

Estimate the least sum.

• close to 0

• close to 1

• close to 2

• 1

Multiple Choice

Suppose you played Getting Close with only these game cards:

Which two cards have the greatest sum?

• 0.5 and 0.25

• 0.25 and 0.9

• 0.75 and 0.9

• 0.75 and 0.5

Multiple Choice

Suppose you played Getting Close with only these game cards:

Which two cards have the least sum?

• 0.5 and 0.25

• 0.25 and 0.125

• 0.5 and 0.75

• 0.75 and 0.9

Multiple Choice

Suppose you played Getting Close with only these game cards:

Estimate the greatest sum.

• close to 1

• 1

• close to 2

• 2

Multiple Choice

Suppose you played Getting Close with only these game cards:

Estimate the least sum.

• 0

• closet to 0

• 1

• closet to 1

Multiple Choice

Suppose you played Getting Close with only these game cards:

Which two cards have the greatest sum?

• 3/10 and 1/5

• 1/5 and 0.25

• 3/4 and 0.33

• 0.25 and 0.33

Multiple Choice

Suppose you played Getting Close with only these game cards:

Estimate the greatest sum.

• close to 0

• close to 1

• close to 2

• 1

Multiple Choice

Suppose you played Getting Close with only these game cards:

Which two cards have the least sum?

• 1/5 and 0.25

• 3/10 and 0.33

• 1/5 and 3/4

• 0.25 and 0.33

Multiple Choice

Suppose you played Getting Close with only these game cards:

Estimate the least sum.

• closet to 2

• closet to 1

• closet to 0

• 1

Multiple Choice

Estimate each sum to the nearest whole number. Explain how you made each estimate.

• 2/3 + 1/5

• closet to 0

• closet to 1

• closet to 2

• closet to 3

Multiple Choice

Estimate each sum to the nearest whole number. Explain how you made each estimate.

• closet to 5

• 5

• closet to 6

• 6

Multiple Choice

Estimate each sum to the nearest whole number. Explain how you made each estimate.

• closet to 1

• closet to 2

• 1

• 2

How do you know which is least and which is greatest?

Summary: Estimating Sums with Benchmarks

1. Find the greatest sum by adding the largest numbers. Estimate the sum. 2. Identify the two cards with the least sum by adding the smallest numbers. Estimate the sum. 3. For decimal and fraction cards, estimate the sum by rounding to the nearest whole number. 4. Use benchmarks to estimate sums and compare different combinations of cards.