MathIsimple
Unit 1: Lesson 4

Three-Digit Subtraction With Regrouping

Learn to regroup and borrow when subtracting three-digit numbers! When the top digit is smaller, we 'borrow' from the next column. It's like breaking a ten-dollar bill to get ones! 💵🔄

35-40 min
Medium
Recognizing Borrowing
Borrowing from Tens
Borrowing from Hundreds
Multiple Regrouping

🎯 Interactive Practice Activities!

Master borrowing and regrouping with these engaging activities!

When Do We Borrow?

Learn to identify when borrowing is needed in subtraction!

Easy
5 minutes
👀

🔍 Look at this problem: 523 - 178. Do we need to borrow in the ones place?

Borrow from Tens Place

Practice borrowing when subtracting in the ones column!

Medium
7 minutes
🎯

🔄 Let's solve 523 - 178 step by step! Drag the steps in order.

🖱️ Drag options below to the correct boxes (computer) or click to move (mobile)

📍 Target Zones

📍Step 1: Solve Ones Column
Waiting...
📍Step 2: Solve Tens Column
Waiting...
📍Step 3: Solve Hundreds Column
Waiting...
📍Step 4: Write Answer
Waiting...

🎯 Draggable Options

1️⃣Ones: Can't do 3-8, so borrow 1 ten. Now 13-8=5
2️⃣Tens: 2 became 1 after borrowing. Can't do 1-7, borrow 1 hundred. Now 11-7=4
3️⃣Hundreds: 5 became 4 after borrowing. Now 4-1=3
4️⃣Final answer: 345
Progress:
0 / 4

Solve with Borrowing

Apply regrouping to solve challenging subtraction problems!

Medium
8 minutes
🎪

🎪 A circus has 614 tickets. They sell 387 tickets. How many tickets are left?

Find Borrowing Errors

Spot the mistakes in regrouped subtraction problems!

Medium
7 minutes
🔎

🔍 Click on all the problems where borrowing was done CORRECTLY!

Click all correct options

Selected: 0
📚Master Borrowing Concepts

Learn Borrowing and Regrouping

Explore 7 comprehensive knowledge cards about borrowing strategies!

What is Borrowing?

Borrowing (also called regrouping) in subtraction happens when the top digit is smaller than the bottom digit. We 'borrow' from the next column to the left - just like breaking a $10 bill into ten $1 bills! This lets us subtract successfully. Borrowing is the opposite of carrying in addition!

🌟Examples:

Borrowing = 'breaking apart' a larger place value to help a smaller one

Example: Can't do 3-8? Borrow 1 ten, making 3 become 13

When we borrow 1 ten, we take it from the tens place (reducing it by 1)

The borrowed ten becomes 10 ones, so 3 + 10 = 13 ones

Now we can subtract: 13 - 8 = 5!

Pro Tip! 💡

Cross out the number you're borrowing from and write the new (smaller) number above it. Write the borrowed amount next to the digit you're helping. This keeps your work organized!

Common Mistake Alert! ⚠️

Forgetting to reduce the number you borrowed from! If you borrow 1 ten from 5 tens, the 5 becomes 4. Don't forget to change it!

Real-World Use 🌍

Money exchanges! Need to pay 8 dollars but only have 3 ones? Break a $10 bill (borrow from tens) to get thirteen $1 bills. That's borrowing in real life!

Practice Idea! 🎯

Use play money! Practice 'breaking' bills: trade one $10 for ten $1s, or one $100 for ten $10s. Make borrowing physical and concrete!

When Do We Need to Borrow?

Before subtracting any column, ask: 'Is the top number bigger than or equal to the bottom number?' If YES, subtract normally. If NO (top is smaller), you must borrow! This preview helps you plan and avoid mistakes. Checking is a critical habit!

🌟Examples:

Check each column: Is the top digit smaller than the bottom digit?

Example: In 523 - 178, look at ones: 3 < 8, so we need to borrow!

Example: In 742 - 235, look at ones: 2 < 5, need to borrow!

If top digit ≥ bottom digit, no borrowing needed in that column

Always check BEFORE you start subtracting!

Pro Tip! 💡

Do a quick 'borrowing scan' before solving: glance at each column from right to left. Mark where you'll need to borrow. This mental preparation makes solving smoother!

Common Mistake Alert! ⚠️

Not checking before subtracting! Some students start subtracting and get confused mid-problem. Take 5 seconds to scan first - it saves time!

Real-World Use 🌍

Planning ahead! Just like checking if you have enough money before buying, checking if you need to borrow helps you plan your work!

Practice Idea! 🎯

Play 'Borrow or Not?' - Look at subtraction problems and quickly decide which columns need borrowing. Practice until it's automatic!

Borrowing from the Tens Place

When you can't subtract in the ones column, borrow 1 ten from the tens place. This borrowed ten equals 10 ones, which you add to the ones column. For example, borrowing from 52 gives you 4 tens and 12 ones. Now you can subtract! This is the most common type of borrowing.

🌟Examples:

Step 1: See that 3 < 8 in ones column - can't subtract!

Step 2: Borrow 1 ten from tens place (5 tens becomes 4 tens)

Step 3: That borrowed ten = 10 ones. Add to ones place: 3 + 10 = 13

Step 4: Now subtract: 13 - 8 = 5

Step 5: Continue with tens column (now 4 tens, not 5)

Pro Tip! 💡

Say it out loud: 'I'm borrowing 1 ten. 5 tens becomes 4 tens. The borrowed ten gives me 10 more ones. 3 + 10 = 13.' Talking through it helps!

Common Mistake Alert! ⚠️

Forgetting that 1 ten = 10 ones! When you borrow, you're adding 10 to the ones column, not 1. So 3 becomes 13, not 4!

Real-World Use 🌍

Breaking bills! You have $52 (5 tens + 2 ones). Need to give someone $8 but only have $2 in ones? Break a $10 bill: now you have $40 + $12 = $52 still, but now you can pay $8!

Practice Idea! 🎯

Draw it out! Show 53 as 5 tens-rods and 3 ones-cubes. When borrowing, physically break 1 rod into 10 cubes. Seeing it helps understanding!

Borrowing from the Hundreds Place

Borrowing from hundreds works exactly like borrowing from tens - the numbers are just bigger! When you can't subtract in the tens column, borrow 1 hundred from the hundreds place. That borrowed hundred equals 10 tens. Add those 10 tens to your tens column, and now you can subtract!

🌟Examples:

When tens column can't subtract, borrow from hundreds

Example: Can't do 1 ten - 7 tens? Borrow 1 hundred!

1 hundred = 10 tens, so add to tens column: 1 + 10 = 11 tens

The hundreds place decreases by 1 after borrowing

Now you can subtract: 11 tens - 7 tens = 4 tens

Pro Tip! 💡

The process is the same at every place value! If you master borrowing from tens, you've mastered borrowing from hundreds too. Just remember: 1 hundred = 10 tens!

Common Mistake Alert! ⚠️

Getting confused by larger numbers. Remember: borrowing 1 hundred gives you 10 tens, not 100 tens! Just like borrowing 1 ten gives 10 ones.

Real-World Use 🌍

Money: Can't make change from 1 ten ($10) for something costing $70? Break a $100 bill into ten $10 bills. Now you have enough! That's borrowing hundreds!

Practice Idea! 🎯

Practice: 'What is 1 hundred in tens?' (10 tens!), 'What is 1 ten in ones?' (10 ones!). Master these facts and borrowing becomes easy!

Multiple Borrowing (Cascade)

Sometimes you need to borrow multiple times in the same problem! This is called 'cascade borrowing.' Handle each column one at a time, from right to left. Borrow when needed, update the column you borrowed from, then move on. Take it step by step and stay organized - you've got this!

🌟Examples:

Some problems need borrowing in multiple places!

Example: 523 - 178 needs borrowing in ones AND tens

First: Borrow from tens for ones (13 - 8 = 5)

Second: Can't do 1 ten - 7 tens, so borrow from hundreds (11 - 7 = 4)

Finally: Subtract hundreds (4 - 1 = 3). Answer: 345!

Pro Tip! 💡

Work slowly and methodically! Do one column completely (including any borrowing) before moving to the next. Rushing leads to errors in multiple-borrowing problems.

Common Mistake Alert! ⚠️

Losing track of which numbers changed after borrowing! Keep your work neat. Cross out old numbers and write new ones clearly above them.

Real-World Use 🌍

Complex transactions often need multiple 'exchanges': Breaking a $500 bill to make change, or using multiple coin exchanges. Multiple steps are common in real life!

Practice Idea! 🎯

Start with single-borrowing problems, then progress to double borrowing. Build confidence gradually. Mastery comes with practice!

Checking Borrowed Answers

Borrowing adds complexity, which means more chances for errors. Always check your work! The best method is adding your answer to the number you subtracted - if you get the original number, you're correct! You can also estimate to see if your answer makes sense. Checking is part of being a good mathematician!

🌟Examples:

Method 1: Add your answer to the subtracted number - should equal the original!

Example: 523 - 178 = 345. Check: 345 + 178 should = 523 ✓

Method 2: Estimate before solving - 523 ≈ 500, 178 ≈ 200, so answer ≈ 300 ✓

Method 3: Redo the problem carefully, watching your borrowing steps

Always check problems with borrowing - it's easy to make small mistakes!

Pro Tip! 💡

Keep your check work! Write '345 + 178 = 523 ✓' next to your answer. This shows you verified it. If the check fails, you know to recheck your borrowing!

Common Mistake Alert! ⚠️

Not checking, or checking but ignoring when it doesn't work out! If 345 + 178 doesn't equal 523, that's your signal to find the error. Don't ignore red flags!

Real-World Use 🌍

Any important calculation - money, measurements, time, scores - should be checked! Accuracy matters when real consequences are involved!

Practice Idea! 🎯

Make checking automatic: After every borrowing problem, immediately check with addition before moving to the next problem. Build the habit!

Mastering Subtraction with Borrowing

Mastering subtraction with borrowing is a major achievement! Once you understand it, you'll use these skills in fourth grade, fifth grade, and beyond. You'll even use borrowing concepts in algebra! The time you spend now learning this well will pay off for years. Keep practicing and celebrating your progress!

🌟Examples:

Borrowing is one of the hardest skills in elementary math - be proud of learning it!

Practice makes it easier! The more you borrow, the more automatic it becomes

Look for patterns: borrowing always follows the same steps

Build both accuracy AND speed - but accuracy comes first!

You're building skills that will help in all future math! 🎉

Pro Tip! 💡

Create a 'borrowing checklist': 1) Check if borrowing needed, 2) Borrow and adjust, 3) Subtract, 4) Move to next column, 5) Check answer. Following steps prevents mistakes!

Common Mistake Alert! ⚠️

Getting frustrated and giving up! Borrowing IS hard - that's normal! Break it into small steps, practice a little each day, and celebrate small wins. You WILL master it!

Real-World Use 🌍

Beyond math: borrowing teaches valuable life skills like breaking big problems into steps, staying organized under complexity, and checking your work. These skills transfer to everything!

Practice Idea! 🎯

Set achievable goals: 'This week, I'll master single-borrowing problems.' Celebrate when you reach each goal, then tackle the next challenge!