2-Digit Subtraction with Place Value Disks - Match Up | Teach Starter - Free Printable

The image shows an educational activity titled "Subtraction within 100", designed to help students practice subtraction using place value discs (also known as base-ten blocks). The task involves solving subtraction problems and matching them to their correct answers.

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🔍 Understanding the Activity

#### ✔ Goal
Students are to:
1. Solve subtraction problems.
2. Use place value discs (representing hundreds, tens, and ones) to model the subtraction.
3. Match each problem card to its correct answer card.

There are 36 task cards, and students will make 18 sets of 2 matches (problem + answer).

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🧮 How Place Value Discs Work

- H = Hundreds
- T = Tens
- O = Ones

Each disc represents:
- One pink disc in the Tens column = 10
- One blue disc in the Ones column = 1

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🔢 Let’s Solve the Examples Shown

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#### 🔹 Example 1:
Problem:
```
92
- 54
```

Step-by-step:
- Start with 92: 9 tens and 2 ones
- Subtract 54: 5 tens and 4 ones

But we only have 2 ones — not enough to subtract 4 ones. So we regroup (borrow):

✔ Regroup: Take 1 ten from the tens place → now we have:
- 8 tens and 12 ones

Now subtract:
- Ones: 12 - 4 = 8
- Tens: 8 - 5 = 3

✔ Answer: 38

✔️ Matches the card showing 38.

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#### 🔹 Example 2:
Problem:
```
56
- 37
```

Start with 56: 5 tens, 6 ones
Subtract 37: 3 tens, 7 ones

We need to subtract 7 ones but only have 6 → regroup!

✔ Regroup: Take 1 ten → now have:
- 4 tens, 16 ones

Now subtract:
- Ones: 16 - 7 = 9
- Tens: 4 - 3 = 1

✔ Answer: 19

✔️ Matches the card showing 19.

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#### 🔹 Example 3:
Problem:
```
35
- 12
```

35: 3 tens, 5 ones
12: 1 ten, 2 ones

No regrouping needed:
- Ones: 5 - 2 = 3
- Tens: 3 - 1 = 2

✔ Answer: 23

✔️ Matches the card showing 23.

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✔ Final Answers:

| Problem | Answer |
|--------|--------|
| 92 - 54 | 38 |
| 56 - 37 | 19 |
| 35 - 12 | 23 |

These match the answer cards shown in the image.

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🎯 How Students Should Use This

1. Cut out all 36 cards.
2. For each subtraction problem, use place value discs to model the numbers.
3. Perform subtraction with regrouping if needed.
4. Find the card with the correct answer and match it.

This helps build number sense, regrouping skills, and visual understanding of subtraction.

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💡 Teaching Tip:

Use physical discs or counters to reinforce the concept. Encourage students to say aloud:
> “I can’t take away more ones than I have, so I’ll break a ten into 10 ones.”

This builds confidence in regrouping.

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✔ Conclusion:
The activity is well-designed for teaching subtraction within 100 using place value understanding. The examples shown are correctly solved, and the matching system reinforces learning through hands-on engagement.