This worksheet looks at the relationship between fractions and division. It is important that children understand that finding one half of a number is equivalent to dividing by 2, that finding one quarter of a number is the same as dividing the number by 4 and to find one fifth is equivalent to dividing by 5. Plenty of practice is needed with this before children go on to find, for example, two fifths, or three fifths of numbers.
Most of these questions should be calculated mentally, although rough jottings may help. It might be a help to remember that finding a quarter of a number can be found by halving and then halving again. A fifth can be found by dividing by ten and doubling the answer, although if the number is not divisible by 10 it might be easier to do a quick pencil and paper calculation.