🍕 7th grade math · Fractions & Decimals
Negative fractions
Match the bottoms first, then use the sign rules on the tops. −3/4 + 1/6: the common bottom is 12. −9/12 + 2/12 = −7/12.
Worked example
512 − (−13)
Answer: 34
Same rule as always: make the pieces match first. In twelfths, 512 is 512 and −13 is −412. Start at 512 and take away 412 — that is 4 twelfths to the right, landing on 912 = 34. So the answer is 34.
For grown-ups: Negative fractions; all operations with rational numbers. Below: three problems to try with the worked answers, and a free printable sheet. Children can practise the same skill as a game, with no sign-up and no ads.
- CCSS 7.NS.A.1–3
What this practises, for teachers
Practices negative fractions; all operations with rational numbers (7.NS.A.1–3). A printable sheet with its answer key, worked answers on the page, no accounts.
Try three
- 116 + (−2512)
Show the answer and how
Answer: −114Same rule as always: make the pieces match first. In twelfths, 116 is 1412 and −2512 is −2912. Start at 1412 and add 2912 — that is 29 twelfths to the left, landing on −1512 = −114. So the answer is −114. - −112 + (−11112)
Show the answer and how
Answer: −3512Same rule as always: make the pieces match first. In twelfths, −112 is −1812 and −11112 is −2312. Start at −1812 and add 2312 — that is 23 twelfths to the left, landing on −4112. So the answer is −3512. - 118 + (−212)
Show the answer and how
Answer: −138Same rule as always: make the pieces match first. In eighths, 118 is 98 and −212 is −208. Start at 98 and add 208 — that is 20 eighths to the left, landing on −118. So the answer is −138.
Before and after
Learn first: Divide fractions (6th)
Name: ____________________Date: ____________Score: ____ / 12
Negative fractions (7th grade)
- −112 − 2112
- 116 − (−34)
- −134 + (−123)
- 23 + (−16)
- −34 + 18
- 1712 + (−278)
- 23 + (−123)
- 12 + (−56)
- −58 − 216
- −118 + (−212)
- −2112 + 156
- −134 + 11112
Answer key
- −3712
- 11112
- −3512
- 12
- −58
- −1724
- −1
- −13
- −21924
- −358
- −14
- 16