MMati Learning Hub

TOPIC 2 · GRADES 3–4

Subtraction and Regrouping

Subtract by place value and exchange 1 ten for 10 ones.

BIG IDEA

If a place does not contain enough units to subtract, exchange 1 unit from the place to its left for 10 units in the current place.

WHAT TO KNOW

  • Line up place values before subtracting.
  • One borrowed ten becomes ten ones, so decrease the tens digit by 1 and add 10 to the ones.
  • Add the difference to the smaller number to check your work.

WATCH OUT

Regrouping does not change the number's value; it only changes how the same amount is represented.

TRY IT

Use the step control to see 52 become 4 tens and 12 ones before subtracting.