Here we have our first two free maths worksheets on subtraction for Year 2. Both these pages are about subtracting whole tens, with a number line to help. As stated in the Year 1 subtraction worksheets, a number line is really useful for helping children gain confidence with subtraction.
Make sure that they are competent and confident with counting up and down in tens, up to 100, before trying these, as success depends on this ability.