Compute 1 1/2 - (-7/5). Give an exact simplified answer.
Exact result: ____________________
CCSS 7.NS.A.1 · signed addition & subtraction
Add and Subtract Rational Numbers Worksheet Generator
Practice addition and subtraction across rational forms instead of isolating integers from fractions and decimals. Every answer is computed with exact numerator/denominator arithmetic, so a decimal-looking prompt never creates a hidden rounding rule.
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Add & Subtract Rational Numbers
Add & subtract rational numbers · Grade 7 standard · Seed 271701
1.
2.
Compute 16/5 - 1.5. Give an exact simplified answer.
Exact result: ____________________
3.
Compute 4 - (-3 1/2). Give an exact simplified answer.
Exact result: ____________________
4.
Compute 3 1/3 + 27/8. Give an exact simplified answer.
Exact result: ____________________
5.
Compute 0.6 + 1/10. Give an exact simplified answer.
Exact result: ____________________
6.
Compute -7/6 - 5/2. Give an exact simplified answer.
Exact result: ____________________
7.
Compute 5 1/6 - (-3.5). Give an exact simplified answer.
Exact result: ____________________
8.
Compute 3.8 + (-27/10). Give an exact simplified answer.
Exact result: ____________________
9.
Compute -1/5 + (-2). Give an exact simplified answer.
Exact result: ____________________
10.
Compute -4 - (-3 3/4). Give an exact simplified answer.
Exact result: ____________________
Exact-construction rule: operations use normalized integer numerator/denominator pairs, number-line positions use exact ticks, repeating decimals come from remainder cycles, and money contexts use exact cents. No answer depends on binary floating-point rounding.
Adding and subtracting across fractions and decimals
This skill treats integers, fractions and decimals as one system. Every answer is computed with exact numerator and denominator arithmetic, so a decimal-looking prompt cannot introduce a rounding rule the student did not choose.
When to move students on
Once students can rewrite subtraction as adding the opposite without prompting, they are ready for the multiplication and division page. Keep the number-line page nearby for students who need to see a sign change as movement.
Sign handling in worked problems
- −2.5 + 1 3/4: write −2.5 as −10/4 and 1 3/4 as 7/4, so the sum is −3/4.
- 3/8 − (−1/4): subtracting a negative is adding a positive, so 3/8 + 2/8 = 5/8.
- −7 − (−7) = −7 + 7 = 0, showing that a number minus itself is always zero.
Sign errors to expect
- Treating −(−3) as −3.
- Adding two negatives and reporting a positive sum.
- Converting a decimal to a rounded fraction partway through the problem.
Teacher tip 1
Treat subtraction as adding the additive inverse when sign changes become confusing: p - q becomes p + (-q).
Teacher tip 2
For opposite signs, subtract absolute values and keep the sign of the number farther from zero: -5 + 3 = -(5 - 3) = -2.
Teacher tip 3
For same signs, add absolute values and keep that sign: -5 + (-3) = -8.
Teacher tip 4
Two negatives only combine to a positive when subtracting a negative, -(-3) = +3, not when adding two negatives.
Teacher tip 5
Keep fraction and decimal conversions exact; do not round before the final result.
Continue the 7.NS progression
Move to another Grade 7 rational-number skill
Common questions
Do these worksheets mix fractions and decimals?
Yes. Standard and challenge modes deliberately mix signed fractions, decimals, and mixed numbers so students practice the full rational-number system.
Are answers rounded?
No. Results are simplified exactly; terminating decimal equivalents may be shown alongside the exact fraction.
What is the most common sign error to watch for?
Reading -5 - 3 as -5 + 3. Subtracting a positive moves further negative to -8; only subtracting a negative moves back toward positive.
Does 7.NS.A.1 expect a number-line explanation?
Yes. The standard asks students to show sums and differences as movement on a number line and to explain p + q as a distance from p in the direction of q's sign, so pair this with the number-line route.