I’ve heard many people say they did endless amount of sums when they went to school. The word sum actually means to add and catches many children out when it comes to a test. E.g. Find the sum of eight and four = 8 + 4
The other commonly used word, which causes confusion, is product. The means to multiply and marks are often lost when a child can’t recall what the word means. E.g. Find the product of six and seven = 6 x 7
I find the best way to help this is to keep using the words in a sentence so a child gets used to these ‘alien’ words. Try to do this at home, it really will help.