Subtraction with Borrowing

Subtraction with Borrowing (Regrouping)

What you'll learn

What to do when the top digit is smaller than the bottom digit in a column.
The idea of borrowing (regrouping): 1 ten = 10 ones, 1 hundred = 10 tens.
To subtract 2-digit and 3-digit numbers that need one or more borrows.
Real-life links — sharing money, using up craft supplies, and school canteen bills.

Key concepts

Level 1 — Core idea

Verbal: 52 − 27: in the ones place, 2 is smaller than 7, so we cannot subtract directly — we borrow.

Symbolic: Borrow 1 ten from the tens place. 52 becomes 4 tens and 12 ones (40 + 12).

Visual:

  4 12
  5  2
− 2  7
------
  2  5

12 − 7 = 5 (ones), then 4 − 2 = 2 (tens). Answer: 25.

Level 2 — Going deeper

Borrowing can happen in more than one place for 3-digit numbers: first borrow from tens for ones, then (if needed) from hundreds for tens. Always regroup one place at a time, from right to left.

NCERT anchor

NCERT Math Mela, Class 3 — Chapter 9 (House of Hundreds) introduces regrouping tens and ones using bundles of sticks and place-value blocks.

Worked example

A basket has 43 apples. 28 are given away. How many are left?

Step 1 — Ones: 3 is smaller than 8, so borrow 1 ten.
Step 2 — 43 becomes 3 tens and 13 ones (30 + 13).
Step 3 — Ones: 13 − 8 = 5
Step 4 — Tens: 3 − 2 = 1
Answer: 15 apples left

Find 502 − 236.

Step 1 — Ones: 2 − 6 needs a borrow. Borrow from tens (0), so borrow from hundreds first.
Step 2 — Regroup 502 as 4 hundreds, 9 tens, 12 ones.
Step 3 — Ones: 12 − 6 = 6
Step 4 — Tens: 9 − 3 = 6
Step 5 — Hundreds: 4 − 2 = 2
Answer: 266

Common mistakes

Mistake	Why	Fix
52 − 27 = 35 (subtracting smaller from larger digit each column, ignoring borrow)	Skipping the borrow step	Borrow first: 12 − 7 = 5, 4 − 2 = 2 → 25
Forgetting to reduce the tens digit after borrowing	Only adding 10 to ones, not subtracting 1 from tens	Always do both: +10 to ones, −1 from tens
Getting stuck when tens digit is 0	Not knowing you can borrow from hundreds	Borrow from hundreds into tens first, then from tens into ones

Quick check

What is 61 − 38?
Subtract 47 from 83.
Find 304 − 158.
Stretch: Rani has ₹50. She spends ₹36. How much money does she have left? (₹14)

Revision tip: Say it aloud: "Can't subtract? Borrow a ten (or hundred), then subtract."

Open the Practice tab for graded questions on Subtraction with Borrowing.

Subtraction with Borrowing