My Child Keeps Getting Subtraction with Borrowing Wrong – From 70% Errors to 10%
Subtraction with borrowing was my daughter's nightmare for months. 52-28 = 36? I thought she was bad at math. Turns out she just wasn't taught the right way.
"What's 52 minus 28?" – "36!" My daughter answered without hesitation. I looked again: 52 - 28 = 24, not 36. She was off by 12! This kept happening for six months straight. She could do addition with carrying perfectly, but subtraction with borrowing? 70% wrong. I thought she was bad at math. But after researching, I realized: she's not bad at math, she just wasn't taught the right way.
Why Is Subtraction with Borrowing Harder Than Addition?
Many parents assume: if they can add, they can subtract. But it's not that simple.
Addition with carrying: Child adds two numbers, if over 10, they "carry 1" to the left column. Simple logic: have extra, move it over.
Subtraction with borrowing: Child must "borrow" from the left column, then "pay back" after calculating. Opposite logic: not enough, go borrow.
The problem: the brain is used to "carrying", now it must do "borrowing" – the opposite concept. Very easy to mix up.
Common Errors My Child Made
I sat and watched her work, discovering these errors:
Error 1: Subtracting in Reverse
52 - 28: She sees 2 < 8, doesn't know to borrow, so she does 8 - 2 = 6. Gets 36 instead of 24.
Error 2: Borrowing But Forgetting to Reduce
She knows to borrow 1 from tens so 2 becomes 12. 12 - 8 = 4, correct. But for the tens column, she still does 5 - 2 = 3 (forgot to subtract the 1 she borrowed). Gets 34 instead of 24.
Error 3: Borrowing When Not Needed
For problems that don't need borrowing like 56 - 23, she still borrows because "it feels familiar." Gets wrong answer.
I realized: She doesn't understand the essence of borrowing. She's just following a procedure without knowing why. When you don't understand, you make mistakes.
How I Retaught Her From Scratch
I decided to abandon the old method and start over with a visual approach.
Step 1: Use Real Objects So She Can 'See' Borrowing
I took 52 candies: 5 bags (10 candies each) and 2 loose candies. Said to her: "Mom wants to take 28 candies. Can you help?"
She looked at the 2 loose candies and said: "There's not enough for 8, Mom." I asked: "So what do we do?" She thought then said: "We have to open a bag."
That's it! She just discovered "borrowing" naturally on her own.
Step 2: Mark When Borrowing
I taught her: Every time you borrow, write a small dot above the number you borrowed from. When calculating that column, see the dot = remember to subtract 1 more.
Example: 52 - 28 - Ones place: 2 < 8 → borrow 1, write dot above 5 - 12 - 8 = 4 ✓ - Tens place: see dot → 5 - 1 - 2 = 2 ✓ - Result: 24 ✓
Step 3: Say 'Borrow 1' Out Loud
I had her say "Borrow 1!" out loud every time she needed to borrow. The brain remembers through sound, helping her not forget.
Step 4: Practice Consistently with Immediate Feedback
Every day she did 10 subtraction with borrowing problems. The key was immediate feedback: right means know it's right, wrong means know to fix it. I let her use an app for automatic grading – more convenient than me checking each problem.
Using Soroban So She Can 'See' Numbers
Besides the method above, I also had her learn Soroban. With the abacus, she can "see" numbers visually.
When doing 52 - 28 on Soroban:
- •She represents 52 on the abacus
- •Subtract 8 from ones place: not enough beads → must borrow 1 from tens
- •Move 1 bead down from tens, add 10 beads to ones
- •Now have 12 beads in ones, subtract 8 → 4 left
- •Continue subtracting 2 from tens: 4 - 2 = 2
- •Result: 24
"Borrowing" becomes clear when she sees herself moving beads. No longer abstract.
Results After 3 Weeks
Week 1: Still getting 50% wrong, but understood the concept.
Week 2: About 30% errors. She started feeling more confident.
Week 3: Only 10% errors. And more importantly, when she makes mistakes, she knows where to look to fix them.
On a 15-minute class test, she got a 9/10. Teacher's note: "Clear improvement, subtraction with borrowing done well."
Tip: Don't give too many problems at once. 10 problems/day, but consistently. Persist for 2-3 weeks and you'll see results.
What I Learned
1. Don't assume they understand: Following a procedure doesn't mean understanding. Ask: "Why did you do this step?" to check.
2. Visual is more important than theory: Young children learn with eyes, with hands. Use candies, use abacus, use images – much more effective than explaining with words.
3. Immediate feedback helps learn faster: When kids know they're wrong immediately, they can fix it. If they finish the whole worksheet and then find out it's wrong, they don't know where they went wrong.
4. Patience is key: 3 weeks is not long. Don't expect changes after 2-3 days.
Subtraction with borrowing is genuinely difficult. Many 3rd-4th graders still get it wrong. But with the right teaching method and consistent practice, any child can master it.
Sorokid has subtraction with borrowing exercises with visual aids. Kids 'see' borrowing through the abacus – understanding the concept instead of just memorizing steps.
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