Numbers & operations · TEKS 7.3A, 7.3B
Operations with rational numbers
Fractions, decimals and negatives follow the same rules as whole numbers. Keep careful track of signs.
Key steps
- Add or subtract fractions: get a common denominator first.
- Multiply fractions: top × top, bottom × bottom.
- Divide fractions: multiply by the reciprocal ("keep, change, flip").
- Signs for × and ÷: same signs give +, different signs give −.
- Order of operations: × and ÷ before + and −.
Worked example
What is (−3/4) ÷ (1/2) + 2?
- Divide first: (−3/4) × (2/1) = −6/4 = −3/2.
- Add: −3/2 + 2 = −3/2 + 4/2 = 1/2.
- Answer: 1/2
Watch out: Subtracting a negative is adding: 5 − (−3) = 8.
Practice
5 questions with new numbers every set. Get 4 of 5 to mark this topic as practiced.