Math worksheet with fact family problems using triangles and a fun illustration of children playing.

Problem Explanation:

The task involves completing "fact families" for each set of numbers provided in the triangles. A fact family is a group of math facts using the same numbers, typically involving addition and subtraction (for smaller numbers) or multiplication and division (for larger numbers). In this case, we are dealing with addition and subtraction.

Each triangle contains three numbers. Using these three numbers, we need to create:
1. Two addition equations.
2. Two subtraction equations.

Step-by-Step Solution:

#### Problem 4:
The numbers in the green triangle are: 8, 11, 19.

1. Addition Equations:
- \( 8 + 11 = 19 \)
- \( 11 + 8 = 19 \)

2. Subtraction Equations:
- \( 19 - 8 = 11 \)
- \( 19 - 11 = 8 \)

So, the completed fact family is:
\[
\begin{aligned}
&8 + 11 = 19 \\
&11 + 8 = 19 \\
&19 - 8 = 11 \\
&19 - 11 = 8
\end{aligned}
\]

#### Problem 5:
The numbers in the yellow triangle are: 3, 23, 26.

1. Addition Equations:
- \( 3 + 23 = 26 \)
- \( 23 + 3 = 26 \)

2. Subtraction Equations:
- \( 26 - 3 = 23 \)
- \( 26 - 23 = 3 \)

So, the completed fact family is:
\[
\begin{aligned}
&3 + 23 = 26 \\
&23 + 3 = 26 \\
&26 - 3 = 23 \\
&26 - 23 = 3
\end{aligned}
\]

#### Problem 6:
The numbers in the blue triangle are: 22, 3, 25.

1. Addition Equations:
- \( 22 + 3 = 25 \)
- \( 3 + 22 = 25 \)

2. Subtraction Equations:
- \( 25 - 22 = 3 \)
- \( 25 - 3 = 22 \)

So, the completed fact family is:
\[
\begin{aligned}
&22 + 3 = 25 \\
&3 + 22 = 25 \\
&25 - 22 = 3 \\
&25 - 3 = 22
\end{aligned}
\]

Final Answer:

\[
\boxed{
\begin{aligned}
&\text{Problem 4:} \\
&8 + 11 = 19, \quad 11 + 8 = 19, \quad 19 - 8 = 11, \quad 19 - 11 = 8 \\
&\text{Problem 5:} \\
&3 + 23 = 26, \quad 23 + 3 = 26, \quad 26 - 3 = 23, \quad 26 - 23 = 3 \\
&\text{Problem 6:} \\
&22 + 3 = 25, \quad 3 + 22 = 25, \quad 25 - 22 = 3, \quad 25 - 3 = 22
\end{aligned}
}
\]