Daphne replaced light bulbs in her mothers store.

She had 3/4 of a box of light bulbs.

Daphne used 1/3 of the bulbs.

How many light bulbs might be in a full box?

What fraction of the box of light bulbs was left?

Start with 1/3 - 3/4. Find the lowest common demoninator (LCD) which is 12.

4/12 - 9/12.

5/12 are left.

How many light bulbs might be in a full box?

Answer: 1/2 of the box of light bulbs was left.



What fraction of the box of light bulbs was left?

Answer: Any multiple of 12, because 1/4 and 1/3 have a common denominator of 12.

(1/3) * (3/4) = 3/12 = 1/4 used

4/4 - 1/4 = 3/4 left

To find the number of bulbs in a full box, you need a multiple of 3 and 4 which could be:

12, 24, 36, 48, etc.

Use multiples of 12 to find how many light bulbs are in a whole box.