FRACTIONS!
Addition & Subtraction of Unlike Fractions
Model 1
Analysis: Denominators are 3 and 5 (unlike & co-prime), so we use Cross-Multiplication.
23
+
15
=
2 × 5 + 1 × 3
15
=
10 + 3
15
=
13
15
Model 2
Analysis: Denominators are 6 and 4 (unlike, not co-prime), so we find the LCM.
Method: Use the Ladder Method to find LCM.
| 2 | 6, 4 |
| 3, 2 |
LCM = 2 × 3 × 2 = 12
Solve: Convert to equivalent fractions with denominator 12 and solve.
56
-
14
=
5 × 2 - 1 × 3
12
=
10 - 3
12
=
7
12
🎯 Interactive Practice 🎯
Tags
Fractions