This file includes three pages with subtraction problems and one page to choose your own problems. Each workspace has a tens and ones mat for students to show/check their work using base ten drawings.
They will help students gain a conceptual understanding of regrouping as they learn the vertical method.
They need many opportunities to practice showing the step with base ten blocks and then carrying out the step in the vertical method.
I used the blank page in small group practice to differentiate problems.