How parents can help their child with key topics in Maths. Help Sheet for Parents. Designed for the parents of Key Stage 3 pupils in secondary school but would also be so useful in a primary setting. Topics include: finding a fraction of an amount, changing a test score into a percentage, finding a percentage, squares, cubes, multiples, factors, prime numbers, averages, adding, subtracting, multiplying and dividing fractions and area and perimeter.