Unlike denominator word problems, step by step
Adding 2/3 and 1/12 is not hard once the denominators match — the work is noticing they do not.
The question
How much more did Omar use than Kwame?
Omar worked the early shift and used 2/3 kilogram; Kwame came in later and used 1/12 kilogram.
2/3 − 1/12
8/12 − 1/12
7/12 kilogram
- Read it through once. Two amounts, one taken from the other — so the operation is the easy part. The work is that the two fractions are cut into different-sized pieces.
- You cannot subtract them as they stand: 2/3 − 1/12 counts pieces of two different sizes. Find a size they can BOTH be cut into.
- Rewritten over that common denominator: 8/12 − 1/12. Nothing has changed value — the same amounts, counted in the same-sized pieces.
- Now the numerators subtract, and the denominator stays put: 7/12 kilogram.
How it works.
- 01
Read it through once. Two amounts, one taken from the other — so the operation is the easy part. The work is that the two fractions are cut into different-sized pieces.
- 02
You cannot subtract them as they stand: 2/3 − 1/12 counts pieces of two different sizes. Find a size they can BOTH be cut into.
- 03
Rewritten over that common denominator: 8/12 − 1/12. Nothing has changed value — the same amounts, counted in the same-sized pieces.
- 04
Now the numerators subtract, and the denominator stays put: 7/12 kilogram.