How it works
Make decomposing fractions worksheets for the grade 4 skill of writing one fraction as a sum. Sheet type runs from 5/6 as five unit fractions to 7/8 in three parts. Make a new sheet changes the fractions.
Read the full guide
A kindergarten idea with a denominator
Common Core K.OA.3 has kindergarten pupils break a number into pairs in more than one way, 5 = 2 + 3 and 5 = 4 + 1. Grade 4 standard 4.NF.3b asks for the same thing with a denominator attached: 5/8 = 2/8 + 3/8 and 5/8 = 4/8 + 1/8. Texas 4.3(B) matches it, and 3.3(D) starts a year earlier with sums of unit fractions.
A key for many right answers
7/8 can be 1/8 + 6/8, 2/8 + 5/8 or 3/8 + 4/8, and a pupil who writes any of them is correct. The key prints one sample answer, marked one way of many. To check any other, the denominator stays and the numerators add to the one you started with.
- Use Split 1 whole into two fractions before adding past 1. Pupils who know that 3/8 needs 5/8 can make a whole first.
Questions and answers
What does decomposing a fraction mean?
Writing it as a sum of smaller fractions with the same denominator. 3/4 can be 1/4 + 1/4 + 1/4 or 1/4 + 2/4. The smallest pieces are unit fractions, which have a numerator of 1.
Should the parts be reduced to lowest terms?
Not on these sheets. 6/8 = 2/8 + 4/8 is a finished answer, and rewriting the parts as 1/4 and 1/2 hides the fact that the numerators add to 6.
Do the sheets come with answers?
Yes. Page 2 is the answer key. Where many answers are right it shows one, and the line under the sheet's title says how to check others. To keep a copy, press Print and choose Save as PDF. Both pages carry the same sheet code.