This set of maths worksheets is suitable for Year 5 children who have a good knowledge of the times tables and can manipulate numbers 'in their heads'. It is worth pointing out that  It is surprising the number of different strategies we use to calculate mentally. The same type of question can be processed several different ways, often depending on the numbers being use. If we look at some of the questions on these worksheets it will become clearer as to what I mean, as I try to explain how I go about answering them, although you may well have different (and better) alternatives. Question 1: ? x 2 = 120 Looking at the question I immediately thought that I had to halve 120 to get the answer. I did this by halving 12, which is 6 and multiplying by 10, making 60. This was all done in a split second, and I might have be tempted to think I did it in one, but it is important to stop and think of the steps that you go through. Question 2: ? x 4 = 48 I could have halved and halved, or divided by 4, but, in fact, I learned my 12 times table many years ago and I know, instantly,  that 12 x 4 = 48 so the answer of 12 came immediately. Question 3: 41 x ? = 205 The answer was not immediately obvious. I looked at the unit (1) and the unit in the answer (5) and it struck me that I need to multiply by 5. A quick check that 4 x 5 will give me 20 confirmed this. 2. Question 4: 26 x ? = 104 This took a little longer and at first glance I was not certain. I then realised that 25 is a quarter of 100, so 25 x 4 is 100,therefore 26 x 4 would be 104. In just these four similar questions I have used various techniques including halving, multiplying mentally by 10, using knowledge of tables and knowing quarters. These are just a few of the ways of working out the answers and it is well worth asking children how they go about finding the answers.