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Learning Target: Estimate sums and differences with fractions.

Lesson: To estimate a sum, round the fraction first. (You would round it up if it is 1/2 or greater, and down if it was less.) Then estimate the sum.

To estimate a difference, round the fraction first. (You would round it up if the fraction is 1/2 or greater, and down if it was less.) Then estimate the difference.

Example: (Sum)

12 7/8 

+ 15

~ 28

1. Round 7/8 up because it is more than 1/2. 2. Estimate the sum of the numbers.

Example: (Difference)

16 2/9 

- 10

~6

1. Round 2/9 down because it is less than 1/2. 2. Estimate the difference of the numbers.

Links:

Estimating sums and differences with fractions