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Unlike Denominators · Grade 5
Adding & Subtracting Fractions
Name
Date
Correct / 4
1
Concrete
- shade it before you compute it
1. Shade 12 of the first square and 13 of the second. Which shows more?
More:
2. Draw fraction strips for 34 and 12. How much longer is 34?
Longer by:
2
Representational
- grids, strips, and multiples
3. The grid shows sixths. Shade 12 and 13 in it, then add.
12 + 13 =
4. List multiples to find the LCD of 4 and 6. Circle the first match.
4:
6:
LCD =
Roots of Reason
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Stuck? Scan for the anchor chart
Unlike Denominators · Grade 5
Adding & Subtracting Fractions
Name
Date
Correct / 8
3
Abstract
- rename, then add or subtract. Items 9 to 12 are mixed numbers.
5. 13 + 14 =
6. 56 − 12 =
7. 25 + 12 =
8. 78 − 34 =
9. 112 + 213 =
10. 314 − 112 =
11. 23 + 56 =
12. 416 − 223 =
Roots of Reason
rootsofreason.org
Unlike Denominators · Grade 5
Adding & Subtracting Fractions
1
Concrete
1. Shade 12 of the first square and 13 of the second. Which shows more?
More: 1/2
2. Draw fraction strips for 34 and 12. How much longer is 34?
Longer by: 1/4
2
Representational
3. The grid shows sixths. Shade 12 and 13 in it, then add.
12 + 13 = 5/6
4. List multiples to find the LCD of 4 and 6. Circle the first match.
4: 4, 8, ⑫, 16, 20
6: 6, ⑫, 18, 24
LCD = 12
3
Abstract
5. 13 + 14 = 7/12
6. 56 − 12 = 1/3
7. 25 + 12 = 9/10
8. 78 − 34 = 1/8
Mixed numbers - make them improper first.
9. 112 + 213 = 3 5/6
10. 314 − 112 = 1 3/4
11. 23 + 56 = 1 1/2
12. 416 − 223 = 1 1/2
If a student adds denominators in problem 5, don't re-teach the rule - send them back to the sixths grid in problem 3. The grid makes "you can only add matching pieces" impossible to miss.