Number Lines: Sum up to 50 - Practice addition using number lines.

To solve the problem, we need to analyze each number line and determine the starting point, the ending point, and the total distance traveled. This will help us complete the addition sentences.

Step-by-Step Solution:

#### Number Line 1:
- The pink arrow starts at 0 and ends at 35.
- The total distance traveled is 35.
- The addition sentence can be written as:
\[
0 + 35 = 35
\]

#### Number Line 2:
- The pink arrow starts at 0 and ends at 35.
- The total distance traveled is 35.
- The addition sentence can be written as:
\[
0 + 35 = 35
\]

#### Number Line 3:
- The pink arrow starts at 0 and ends at 45.
- The total distance traveled is 45.
- The addition sentence can be written as:
\[
0 + 45 = 45
\]

#### Number Line 4:
- The pink arrow starts at 5 and ends at 45.
- The total distance traveled is 45 - 5 = 40.
- The addition sentence can be written as:
\[
5 + 40 = 45
\]

#### Number Line 5:
- The pink arrow starts at 0 and ends at 50.
- The total distance traveled is 50.
- The addition sentence can be written as:
\[
0 + 50 = 50
\]

Final Answers:

\[
\boxed{
\begin{aligned}
1. & \quad 0 + 35 = 35 \\
2. & \quad 0 + 35 = 35 \\
3. & \quad 0 + 45 = 45 \\
4. & \quad 5 + 40 = 45 \\
5. & \quad 0 + 50 = 50 \\
\end{aligned}
}
\]