Do you have to teach adding and subtracting strategies? One strategy that I always teach is the split strategy. You may refer to it as something else, but this is the strategy where students take a number and split it up into the expanded form and then solve the problem.
I have two worksheets to help your students practice this strategy in both the addition and subtraction form.
You can head over to my blog and read all about how I teach this strategy and then grab these worksheets for free! Head here to check it all out!