Addition & Subtraction Fact Families for Teachers | Perfect for ... - Free Printable

Problem Explanation:

The task involves creating addition and subtraction fact families using the numbers provided in each triangle. A fact family is a group of math facts using the same numbers. For addition and subtraction, if you have three numbers (let's say \(a\), \(b\), and \(c\)), the fact family includes:
- Two addition facts: \(a + b = c\) and \(b + a = c\)
- Two subtraction facts: \(c - a = b\) and \(c - b = a\)

Solution:

#### Triangle 1: Numbers are 1, 2, and 3
1. Addition facts:
- \(1 + 2 = 3\)
- \(2 + 1 = 3\)

2. Subtraction facts:
- \(3 - 1 = 2\)
- \(3 - 2 = 1\)

So, the completed fact family is:
```
1 + 2 = 3
2 + 1 = 3
3 - 1 = 2
3 - 2 = 1
```

#### Triangle 2: Numbers are 4, 6, and 10
1. Addition facts:
- \(4 + 6 = 10\)
- \(6 + 4 = 10\)

2. Subtraction facts:
- \(10 - 4 = 6\)
- \(10 - 6 = 4\)

So, the completed fact family is:
```
4 + 6 = 10
6 + 4 = 10
10 - 4 = 6
10 - 6 = 4
```

#### Triangle 3: Numbers are 2, 5, and 7
1. Addition facts:
- \(2 + 5 = 7\)
- \(5 + 2 = 7\)

2. Subtraction facts:
- \(7 - 2 = 5\)
- \(7 - 5 = 2\)

So, the completed fact family is:
```
2 + 5 = 7
5 + 2 = 7
7 - 2 = 5
7 - 5 = 2
```

#### Triangle 4: Numbers are 1, 4, and 5
1. Addition facts:
- \(1 + 4 = 5\)
- \(4 + 1 = 5\)

2. Subtraction facts:
- \(5 - 1 = 4\)
- \(5 - 4 = 1\)

So, the completed fact family is:
```
1 + 4 = 5
4 + 1 = 5
5 - 1 = 4
5 - 4 = 1
```

Final Answer:

```
1.
1 + 2 = 3
2 + 1 = 3
3 - 1 = 2
3 - 2 = 1

2.
4 + 6 = 10
6 + 4 = 10
10 - 4 = 6
10 - 6 = 4

3.
2 + 5 = 7
5 + 2 = 7
7 - 2 = 5
7 - 5 = 2

4.
1 + 4 = 5
4 + 1 = 5
5 - 1 = 4
5 - 4 = 1
```

\boxed{
\begin{aligned}
&1. \quad 1 + 2 = 3, \quad 2 + 1 = 3, \quad 3 - 1 = 2, \quad 3 - 2 = 1 \\
&2. \quad 4 + 6 = 10, \quad 6 + 4 = 10, \quad 10 - 4 = 6, \quad 10 - 6 = 4 \\
&3. \quad 2 + 5 = 7, \quad 5 + 2 = 7, \quad 7 - 2 = 5, \quad 7 - 5 = 2 \\
&4. \quad 1 + 4 = 5, \quad 4 + 1 = 5, \quad 5 - 1 = 4, \quad 5 - 4 = 1
\end{aligned}
}