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This worksheet helps students practice finding missing numbers in addition and subtraction equations.

Printable math worksheet featuring addition and subtraction equations with missing numbers and a fact triangle hint.

Printable math worksheet featuring addition and subtraction equations with missing numbers and a fact triangle hint.

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You’ve uploaded an image containing a set of arithmetic problems — mostly subtraction and addition equations with missing numbers. The hint says: *“Make a fact triangle to help you solve.”*

Let’s break this down step by step.

---

## 🔍 What is a “Fact Triangle”?

A fact triangle is a visual tool that shows the relationship between three numbers in an addition/subtraction or multiplication/division fact family.

For example, for the numbers 5, 3, and 8:

```
8
/ \
5 3
```

This means:
- 5 + 3 = 8
- 3 + 5 = 8
- 8 - 5 = 3
- 8 - 3 = 5

We’ll use this idea to solve each problem.

---

## ✏️ Solving Each Problem

We’ll go row by row.

---

Row 1:


> 42 - ___ = 38

→ Think: What number subtracted from 42 gives 38?
→ 42 - 38 = 4

Answer: 4

> ___ - 8 = 5

→ Think: What number minus 8 equals 5?
→ 5 + 8 = 13

Answer: 13

---

Row 2:


> 184 - ___ = 65

→ 184 - 65 = 119

Answer: 119

> 39 + ___ = 48

→ 48 - 39 = 9

Answer: 9

---

Row 3:


> 132 - ___ = 101

→ 132 - 101 = 31

Answer: 31

> ___ + 12 = 80

→ 80 - 12 = 68

Answer: 68

---

Row 4:


> ___ - 38 = 174

→ 174 + 38 = 212

Answer: 212

> 27 + ___ = 48

→ 48 - 27 = 21

Answer: 21

---

Row 5:


> ___ - 209 = 116

→ 116 + 209 = 325

Answer: 325

> ___ + 6 = 18

→ 18 - 6 = 12

Answer: 12

---

Row 6:


> 151 - 23 = ___

→ 151 - 23 = 128

Answer: 128

> ___ + 4 = 93

→ 93 - 4 = 89

Answer: 89

---

Row 7:


> 343 - ___ = 91

→ 343 - 91 = 252

Answer: 252

> 31 + ___ = 65

→ 65 - 31 = 34

Answer: 34

---

Row 8:


> 39 - ___ = 38

→ 39 - 38 = 1

Answer: 1

> 152 + 198 = ___

→ 152 + 198 = 350

Answer: 350

---

Row 9:


> 99 - ___ = 72

→ 99 - 72 = 27

Answer: 27

*(Note: There’s no second equation in the last row — only one blank.)*

---

## 🧩 Final Answers (Left to Right, Top to Bottom):

```
4 13
119 9
31 68
212 21
325 12
128 89
252 34
1 350
27
```

---

## 💡 How Fact Triangles Help

For any equation like `A - B = C`, the fact triangle would be:

```
A
/ \
B C
```

So if you know two numbers, you can find the third.

Example: For `___ - 8 = 5`, think of triangle:

```
?
/ \
8 5
```

→ ? = 8 + 5 = 13

Similarly, for `39 + ___ = 48` → think:

```
48
/ \
39 ?
```

→ ? = 48 - 39 = 9

This method reinforces inverse operations and helps build number sense.

---

All problems solved! Let me know if you’d like them formatted in a grid or worksheet style.
Parent Tip: Review the logic above to help your child master the concept of open sentence math worksheet.
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