As with many of these types of question there may well be more than one correct answer. The key to remember is that any correct answer will gain the marks, even if it is an easy one. Taking the first question: you could make it harder and work out that 44 + 17 = 61, but 51 = 10 would gain just as many marks – keep it simple and avoid unnecessary mistakes!
Booster maths worksheet 2
Another page of arithmetic practice aimed at boosting Key Stage 2 SAT scores.