A great maths book on Amazon:
MathsPad on the Ipad
You can use our flash based resources on the ipad if you download a browser called Puffin.
This interactivity challenges pupils to think backwards - it requires them to find all the numbers in the grid that would round to 0.2. You can reload the task to generate a new set of random numbers,so students can practise as often as they like. Why not leave it on the IWB during your lesson and allow pairs of students to come out to the front and have a go? The second task on the interactivity is a standard set of questions allowing students to practise rounding to 1 and 2 decimal places.
You can only ride the SuperTwister if you are more than 120cm tall. Use the information given about these pupils to work out who can definitely ride the Supertwister, who definitely can't, and who we need more information about to be sure. This worksheet gets students thinking about what the lower bounds of numbers might be.