Printable primary math worksheet for math grades 1 to 6 based on - Free Printable

Let's solve each of the factor tree problems on the worksheet. The goal is to fill in the missing numbers by breaking down the given number into its prime factors using a factor tree.

---

1) 90

We are given:
```
90
/ \
? ?
/ \ / \
? ? ? ?
```

And below:
90 = ___ × ___ × ___ × ___

#### Step-by-step:

Start with 90.

- 90 can be split into 9 × 10 (or other pairs like 2×45, 3×30, etc.). But we want to go toward prime factors.
- Let’s use 9 × 10:
- 9 = 3 × 3
- 10 = 2 × 5

So:
```
90
/ \
9 10
/ \ / \
3 3 2 5
```

Now list all prime factors: 3, 3, 2, 5

So:
90 = 2 × 3 × 3 × 5

Or in order: 2 × 3 × 3 × 5

✔ Answer: 2, 3, 3, 5

---

2) 156

Given:
```
156
/ \
? ?
/ \ / \
? ? ? ?
```

Below:
156 = ___ × ___ × ___ × ___

#### Step-by-step:

Split 156.

- 156 is even → divide by 2:
156 = 2 × 78

Now break down 78:
- 78 = 2 × 39

Now 39 = 3 × 13

So:
```
156
/ \
2 78
/ \
2 39
/ \
3 13
```

Prime factors: 2, 2, 3, 13

So:
156 = 2 × 2 × 3 × 13

✔ Answer: 2, 2, 3, 13

---

3) 84

Given:
```
84
/ \
? ?
/ \ / \
? ? ? ?
```

Below:
84 = ___ × ___ × ___ × ___

#### Step-by-step:

Split 84.

- 84 is even → 84 = 2 × 42
- 42 = 2 × 21
- 21 = 3 × 7

So:
```
84
/ \
2 42
/ \
2 21
/ \
3 7
```

Prime factors: 2, 2, 3, 7

So:
84 = 2 × 2 × 3 × 7

✔ Answer: 2, 2, 3, 7

---

4) 210

Given:
```
210
/ \
? ?
/ \ / \
? ? ? ?
```

Below:
210 = ___ × ___ × ___ × ___

#### Step-by-step:

Split 210.

- 210 is even → 210 = 2 × 105
- 105 = 5 × 21
- 21 = 3 × 7

So:
```
210
/ \
2 105
/ \
5 21
/ \
3 7
```

Prime factors: 2, 5, 3, 7

So:
210 = 2 × 3 × 5 × 7

(You can write them in any order since multiplication is commutative.)

✔ Answer: 2, 3, 5, 7

---

✔ Final Answers:

1) 90 = 2 × 3 × 3 × 5
2) 156 = 2 × 2 × 3 × 13
3) 84 = 2 × 2 × 3 × 7
4) 210 = 2 × 3 × 5 × 7

> You can fill these into the blanks under each problem.

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