Mathematics - Addition and Subtraction - Two-digit addition with regrouping - Watch the Regroup

Show base-10 blocks for two numbers (e.g., 38 and 45). Merge the cubes: 8+5=13 cubes. Show them physically: 13 unit cubes in the ones area. Then animate: 10 of those cubes flash and transform into 1 rod, leaving 3 cubes. The rod flies to the tens area. Now count: 3+4+1(new)=8 rods, 3 cubes = 83. Let