Multiplying Fractions
Multiplying fractions is simpler than adding them. You don't need a common denominator - just multiply straight across and simplify.
Formula
a/b x c/d = (axc) / (bxd)
Steps
- Multiply the numerators together
- Multiply the denominators together
- Simplify the resulting fraction
Examples
Example 1: 2/3 x 3/4
(2x3) / (3x4) = 6/12 = 1/2
Example 2: 1/2 x 4/5
(1x4) / (2x5) = 4/10 = 2/5
Cross-Cancellation Shortcut
Before multiplying, you can cancel common factors between any numerator and any denominator. This makes the math easier.
Example: 2/3 x 3/4 -> Cancel the 3s -> 2/1 x 1/4 = 2/4 = 1/2
Multiplying by Whole Numbers
Treat the whole number as a fraction over 1. For example: 5 x 2/3 = 5/1 x 2/3 = 10/3
Quick Tips
- Double-check your inputs for accurate results
- Use parentheses to clarify order of operations
- Results are rounded — consider significant figures
Frequently Asked Questions
Multiply numerators together and denominators together, then simplify.
No, common denominators are only needed for addition and subtraction.
1/2 x 1/3 = 1/6
Yes, cross-cancellation can make the math easier.
2/3 x 3/4 = 6/12 = 1/2