7th Grade · The Number System
KCF
7.NS.A.2c
Definition
A method for dividing fractions: Keep the first fraction, Change division to multiplication, Flip the second fraction (its reciprocal). Then simplify.
Examples
- 3/4 ÷ 2/5 = 3/4 × 5/2 = 15/8.
- 2/5 becomes 5/2 (its reciprocal) while 3/4 stays the same.
Key rule
KCF only works for division; for multiplication, just multiply across.
Memory hook
Keep - Change - Flip.