Printable Brain Teasers for Kids | Woo! Jr. Kids Activities ... - Free Printable

These puzzles involve manipulating matchsticks to form correct mathematical equations. Each puzzle requires you to move, add, or remove one or more matchsticks to make the equation valid. Below is a detailed explanation of how to solve each puzzle:

---

Puzzle 81:

```
[8] + [6] = [5]
```
- The equation is incorrect as `8 + 6 ≠ 5`.
- Solution: Move one matchstick from the `8` to turn it into a `9`, and use that matchstick to change the `5` into a `7`. The equation becomes:
```
[9] + [6] = [15]
```
This is now correct.

---

Puzzle 82:

```
[8] + [5] = [2]
```
- The equation is incorrect as `8 + 5 ≠ 2`.
- Solution: Move one matchstick from the `8` to turn it into a `9`, and use that matchstick to change the `2` into a `7`. The equation becomes:
```
[9] + [5] = [14]
```
This is now correct.

---

Puzzle 83:

```
[11] + [5] = [11]
```
- The equation is incorrect as `11 + 5 ≠ 11`.
- Solution: Remove one matchstick from the first `1` in `[11]` to turn it into `[1]`. The equation becomes:
```
[1] + [5] = [6]
```
This is now correct.

---

Puzzle 84:

```
[5] + [6] = [13]
```
- The equation is incorrect as `5 + 6 ≠ 13`.
- Solution: Move one matchstick from the `5` to turn it into a `9`. The equation becomes:
```
[9] + [6] = [15]
```
This is now correct.

---

Puzzle 85:

```
[12] + [5] = [17]
```
- The equation is incorrect as `12 + 5 ≠ 17`.
- Solution: Move one matchstick from the `12` to turn it into `11`, and use that matchstick to change the `17` into `16`. The equation becomes:
```
[11] + [5] = [16]
```
This is now correct.

---

Puzzle 86:

```
[11] + [0] = [2]
```
- The equation is incorrect as `11 + 0 ≠ 2`.
- Solution: Move one matchstick from the `11` to turn it into `1`, and use that matchstick to change the `2` into `1`. The equation becomes:
```
[1] + [0] = [1]
```
This is now correct.

---

Puzzle 87:

```
[14] - [1] = [13]
```
- The equation is incorrect as `14 - 1 ≠ 13`.
- Solution: Move one matchstick from the `14` to turn it into `11`, and use that matchstick to change the `13` into `12`. The equation becomes:
```
[11] - [1] = [10]
```
This is now correct.

---

Puzzle 88:

```
[20] - [7] = [13]
```
- The equation is incorrect as `20 - 7 ≠ 13`.
- Solution: Move one matchstick from the `20` to turn it into `10`, and use that matchstick to change the `13` into `3`. The equation becomes:
```
[10] - [7] = [3]
```
This is now correct.

---

Puzzle 89:

```
[66] + [5] = [5]
```
- The equation is incorrect as `66 + 5 ≠ 5`.
- Solution: Move one matchstick from the `66` to turn it into `6`, and use that matchstick to change the second `5` into `11`. The equation becomes:
```
[6] + [5] = [11]
```
This is now correct.

---

Puzzle 90:

```
[6] + [5] = [1]
```
- The equation is incorrect as `6 + 5 ≠ 1`.
- Solution: Move one matchstick from the `6` to turn it into `1`, and use that matchstick to change the `1` into `11`. The equation becomes:
```
[1] + [5] = [6]
```
This is now correct.

---

Final Answers:

1. Puzzle 81: `[9] + [6] = [15]`
2. Puzzle 82: `[9] + [5] = [14]`
3. Puzzle 83: `[1] + [5] = [6]`
4. Puzzle 84: `[9] + [6] = [15]`
5. Puzzle 85: `[11] + [5] = [16]`
6. Puzzle 86: `[1] + [0] = [1]`
7. Puzzle 87: `[11] - [1] = [10]`
8. Puzzle 88: `[10] - [7] = [3]`
9. Puzzle 89: `[6] + [5] = [11]`
10. Puzzle 90: `[1] + [5] = [6]`

Boxed Final Answer:
\[
\boxed{
\begin{aligned}
&\text{Puzzle 81: } [9] + [6] = [15] \\
&\text{Puzzle 82: } [9] + [5] = [14] \\
&\text{Puzzle 83: } [1] + [5] = [6] \\
&\text{Puzzle 84: } [9] + [6] = [15] \\
&\text{Puzzle 85: } [11] + [5] = [16] \\
&\text{Puzzle 86: } [1] + [0] = [1] \\
&\text{Puzzle 87: } [11] - [1] = [10] \\
&\text{Puzzle 88: } [10] - [7] = [3] \\
&\text{Puzzle 89: } [6] + [5] = [11] \\
&\text{Puzzle 90: } [1] + [5] = [6] \\
\end{aligned}
}
\]