To multiply fractions, you multiply the numerators together to get the new numerator, and you multiply the denominators together to get the new denominator.
For example: ba×dc=b×da×c$$\frac{a}{b} \times \frac{c}{d} = \frac{a \times c}{b \times d}$$
Problem: 21×43$$\frac{1}{2} \times \frac{3}{4}$$
Step 1: Multiply the numerators: 1×3=3$$1 \times 3 = 3$$
Step 2: Multiply the denominators: 2×4=8$$2 \times 4 = 8$$
Solution: 21×43=83$$\frac{1}{2} \times \frac{3}{4} = \frac{3}{8}$$
Problem: 52×97$$\frac{2}{5} \times \frac{7}{9}$$
Step 1: Multiply the numerators: 2×7=14$$2 \times 7 = 14$$
Step 2: Multiply the denominators: 5×9=45$$5 \times 9 = 45$$
Solution: 52×97=4514$$\frac{2}{5} \times \frac{7}{9} = \frac{14}{45}$$
Problem: 64×32$$\frac{4}{6} \times \frac{2}{3}$$
Step 1: Multiply the numerators: 4×2=8$$4 \times 2 = 8$$
Step 2: Multiply the denominators: 6×3=18$$6 \times 3 = 18$$
Initial Solution: 188$$\frac{8}{18}$$
Step 3: Simplify the fraction (if possible).
Find a common factor for both the numerator and the denominator. In this case, both 8 and 18 are divisible by 2.
Divide both the numerator and the denominator by the common factor: 18÷28÷2=94$$\frac{8 \div 2}{18 \div 2} = \frac{4}{9}$$
Simplified Solution: 94$$\frac{4}{9}$$
Sometimes, it’s easier to simplify before multiplying.
Example: 64×32$$\frac{4}{6} \times \frac{2}{3}$$ can be simplified by noticing that 4 and 2 share a common factor with 6 and 3 respectively.
Simplify 64$$\frac{4}{6}$$ to 32$$\frac{2}{3}$$ by dividing both by 2.
The problem becomes: 32×32$$\frac{2}{3} \times \frac{2}{3}$$
Multiply the numerators: 2×2=4$$2 \times 2 = 4$$
Multiply the denominators: 3×3=9$$3 \times 3 = 9$$
Solution: 94$$\frac{4}{9}$$ (Same as simplifying after multiplying)
The same principle applies when multiplying more than two fractions.
Example: 21×32×43$$\frac{1}{2} \times \frac{2}{3} \times \frac{3}{4}$$
Multiply all numerators: 1×2×3=6$$1 \times 2 \times 3 = 6$$
Multiply all denominators: 2×3×4=24$$2 \times 3 \times 4 = 24$$
Initial Solution: 246$$\frac{6}{24}$$
Simplify the fraction by dividing both numerator and denominator by their greatest common divisor, which is 6.
Simplified Solution: 24÷66÷6=41$$\frac{6 \div 6}{24 \div 6} = \frac{1}{4}$$
Always multiply numerators together and denominators together.
Simplify the fraction after multiplying, if possible, to get the answer in its simplest form.
Simplifying before multiplying can make the calculation easier.
Multiplying Fractions
To multiply fractions, you multiply the numerators together to get the new numerator, and you multiply the denominators together to get the new denominator.
Problem: 21×43
Step 1: Multiply the numerators: 1×3=3
Step 2: Multiply the denominators: 2×4=8
Solution: 21×43=83
Problem: 52×97
Step 1: Multiply the numerators: 2×7=14
Step 2: Multiply the denominators: 5×9=45
Solution: 52×97=4514
Problem: 64×32
Step 1: Multiply the numerators: 4×2=8
Step 2: Multiply the denominators: 6×3=18
Initial Solution: 188
Step 3: Simplify the fraction (if possible).
Find a common factor for both the numerator and the denominator. In this case, both 8 and 18 are divisible by 2.
Divide both the numerator and the denominator by the common factor: 18÷28÷2=94
Simplified Solution: 94
Sometimes, it’s easier to simplify before multiplying.
Example: 64×32 can be simplified by noticing that 4 and 2 share a common factor with 6 and 3 respectively.
Simplify 64 to 32 by dividing both by 2.
The problem becomes: 32×32
Multiply the numerators: 2×2=4
Multiply the denominators: 3×3=9
Solution: 94 (Same as simplifying after multiplying)
The same principle applies when multiplying more than two fractions.
Example: 21×32×43
Multiply all numerators: 1×2×3=6
Multiply all denominators: 2×3×4=24
Initial Solution: 246
Simplify the fraction by dividing both numerator and denominator by their greatest common divisor, which is 6.
Simplified Solution: 24÷66÷6=41
Always multiply numerators together and denominators together.
Simplify the fraction after multiplying, if possible, to get the answer in its simplest form.
Simplifying before multiplying can make the calculation easier.