This is the way I teach addition and subtraction when the horizontal format isn't working or place value concepts are not fully understood and applied. It works every time. Ideally, you need a Place Value Mat and MAB. I just bought plain place mats and ruled them up with a permanent marker.

I have included paper MAB, but the wooden ones are the best and worth every cent.

It breaks down the algorithm process into incremental steps that result in mastery and a thorough understanding of base ten.

The 200 Task Cards target higher order thinking asking the learner to apply the skills they have learnt in real world situations.