Assalamu alaikum,
Fractions are part of a set or a whole. E.g. if you cut an apple into 2 even pieces you have cut it in half 1/2
Do you know what nominators and denominators are?
Denominators are not big and bossy, they are the total amount, nominators show the part of the totals.
We also learnt how to add and subtract fractions – the bottom number the denominator has to be the same. Have you tried adding 3/4 of an apple to 1/3 of an apple, it is not possible.