What is the counting-up (shopkeeper's) method for subtraction?

Instead of taking away, count forward from the smaller number to the larger and add the jumps.

To find 823 − 398, count up from 398 to 823:

• 398 → 400 is 2
• 400 → 823 is 423
• Total jumps: 2 + 423 = 425.

Check: 823 − 398 = 425. ✓ This is how shopkeepers make change. It shines when the two numbers are close, or when the subtrahend is just under a round number.