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Concept 6 of 9

Subtracting with Borrowing

1

Today's big idea

When the top ones are too small, borrow a ten to make them bigger.

52 − 27: borrow, 2 becomes 12, 12−7=5 → 25.

2

How it works

👀 What's going on?

52 − 27: you cannot take 7 from 2. What now?

💡 Here's the trick

54122725borrow: 2 becomes 12, 12−7=5, 4−2=2

When the top ones are too small, borrow a ten to make them bigger.

52 − 27: borrow a ten, so 2 becomes 12. 12 − 7 = 5. Tens: 4 − 2 = 2. The answer is 25.

✍️ Try it

63 − 28: borrow, 3 becomes 13. 13 − 8 = 5. Tens 5 − 2 = 3. → 35.

⚠️ Watch out

After you borrow, the tens digit on top drops by one.

3

Watch me solve one

Quanta solves it

“Watch how I think through one of these — then you try.”

THE PROBLEM

“What is 63 − 28?”

  1. 1

    Ones too small — borrow

    You cannot take 8 from 3, so borrow a ten: 3 becomes 13.

  2. 2

    Now subtract

    13 − 8 = 5, and the tens are now 5 − 2 = 3.

  3. 3

    Answer ✓

    63 − 28 = 35

Now you try one — same steps, different story 👇

4

See it in action

⚡ Time to play!

The top ones are too small — borrow a ten first.

5227

borrow: 2 becomes 12. 12 − 7 = ?

5

Quick check

✅ VERIFICATION

What is 71 − 46?

⚡ Finish the activity above first to answer.

Keep going!

Up next: 3-Digit Addition & Subtraction

Hundreds, tens, ones, column by column.

Concept 7 of 9