How do u decomposition 1 1/4

If you would like and improper fraction it would be 5/4

It is 5/4 if you want it in an improper fraction.

So the rule is multiply down low and add up high.

If you know what 1 (the whole number) times 4 (the denominator) will equal 4

Then add the 1 to the four that will equal 5 with the same denominator which is 4

The answer is 5/4

If that is what you asked