- Fractions can be multiplied and divided just like whole numbers.
Multiplication is simply addition done as many times as the number you need to multiply with. So if 2 x 4 = 2 + 2 +2 + 2, the same rules apply to fractions too.
1/2 x 4 = 1/2 + 1/2 + 1/2 + 1/2 = 2.
But what about if you have to multiply 1/3 x 12. That’s a lot of circles to draw. And what about multiplying 1/3 x 4/5.
A simple rule to multiply fractions:
- Multiply the numerators = new numerator
- Multiply the denominators = new denominator
- numerator / denominator = result.
Sometimes you may not have a denominator - for example when you are multiplying by a whole number. But wait, you do - the denominator is 1. Because 4 is the same as 4/1.
To understand division you have to understand the concept of a reciprocal. The reciprocal of a/b is b/a. Flip the numerator and denominator and you have the reciprocal.
Let’s now use this concept to perform the following fraction division problem.
1/3 divided by 2
=> 1/3 multiplied by 1/2 (reciprocal of 2/1)
=> 1/6 (answer)
So to divide fractions, you convert it to a multiplication problem and use the steps to multiply as before.
- When multiplying a fraction, say 3/4 times 2, the learner might multiply both numerator and denominator by 2.
- Not remembering that 2 is the same as 2/1.