Math Foundations · Numbers and Operations

Fraction Sense — Practice Problems and Worked Solutions

See fractions as numbers and operate on them with meaning.

The formulas you need here

Adding fractions

What it says
Put both fractions over the same bottom, then add only the tops.
When to reach for it
Two fractions with different denominators that need to become one.
Watch out
Never add the denominators. 1/2 + 1/3 is 5/6, not 2/5 — the denominator names the size of the piece, and adding pieces does not change their size.

Six is the shared denominator; only the numerators are summed.

Dividing fractions

What it says
Dividing by a fraction is multiplying by it upside down.
When to reach for it
A fraction divided by a fraction, or a fraction stacked inside a fraction.
Watch out
Flip the second fraction only. Flipping both gives you the reciprocal of the answer.

The divisor is inverted; the dividend is untouched.

16 worked problems

Every step is generated and checked by a computer algebra system.

  1. 1.

    Evaluate and simplify the fraction.

    Answer:

    Step-by-step solution
  2. 2.

    Evaluate and simplify the fraction.

    Answer:

    Step-by-step solution
  3. 3.

    Evaluate and simplify the fraction.

    Answer:

    Step-by-step solution
  4. 4.

    Evaluate and simplify the fraction.

    Answer:

    Step-by-step solution
  5. 5.

    Evaluate and simplify the fraction.

    Answer:

    Step-by-step solution
  6. 6.

    Evaluate and simplify the fraction.

    Answer:

    Step-by-step solution
  7. 7.

    Evaluate and simplify the fraction.

    Answer:

    Step-by-step solution
  8. 8.

    Evaluate and simplify the fraction.

    Answer:

    Step-by-step solution
  9. 9.

    Evaluate and simplify the fraction.

    Answer:

    Step-by-step solution
  10. 10.

    Evaluate and simplify the fraction.

    Answer:

    Step-by-step solution
  11. 11.

    Evaluate and simplify the fraction.

    Answer:

    Step-by-step solution
  12. 12.

    Evaluate and simplify the fraction.

    Answer:

    Step-by-step solution
  13. 13.

    Evaluate and simplify the fraction.

    Answer:

    Step-by-step solution
  14. 14.

    Evaluate and simplify the fraction.

    Answer:

    Step-by-step solution
  15. 15.

    Evaluate and simplify the fraction.

    Answer:

    Step-by-step solution
  16. 16.

    Evaluate and simplify the fraction.

    Answer:

    Step-by-step solution

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