Here are  a set of tricky questions which will test the skills of year 4 children. The fish are all called by numbers, and the challenge is to work out the number names by solving the clues. There are four types of question: 1. 'If I add 20 to my name the answer is 60' type. This type of question can be worked out either by subtraction ( 60 - 20) or adding on from the lower number (add on from 20 to 60). 2. 'If I double my name the answer is 80' type. This type of question can be solved by halving the number (half of 80 is 40). 3. 'I am a 2-digit number. My digits total 5 and have a difference of 3.' This has to be done in two stages and is quite tricky. Find 2-digit numbers where the digits add up to 5 (e.g. 32 or 23 or 14 or 41). Then choose one which has a difference of 3. There are two possible answers (14 or 41). 4. 'If I halve my number and add 4 the answer is 7.' This again involves two steps. Firstly subtract 4 from 7 (3) and then double the answer (6). Go to Problem Solving worksheet