Practice adding multiples of 10 using number lines with this educational worksheet from SplashLearn.

Problem Analysis:

The task involves adding multiples of 10 using a number line. The goal is to solve the given problems step by step and fill in the blanks accordingly.

Step-by-Step Solution:

#### First Problem:
- Given: \( 20 + 30 \)
- Number Line Visualization:
- Start at 20 on the number line.
- Move 30 units to the right (since we are adding 30).
- This lands us at 50.
- Calculation:
\[
20 + 30 = 50
\]
- Expressing in Tens:
- 50 is equivalent to 5 tens.
- Answer:
\[
20 + 30 = 50 = 5 \text{ tens}
\]

#### Second Problem:
- Given: \( 40 + \_\_ = \_\_ = \_\_ \text{ tens} \)
- Number Line Visualization:
- Start at 40 on the number line.
- The arrow moves to 60, indicating an addition of 20.
- Calculation:
\[
40 + 20 = 60
\]
- Expressing in Tens:
- 60 is equivalent to 6 tens.
- Answer:
\[
40 + 20 = 60 = 6 \text{ tens}
\]

#### Third Problem:
- Given: \( \_\_ + \_\_ = \_\_ = \_\_ \text{ tens} \)
- Number Line Visualization:
- The arrow starts at 30 and moves to 80.
- The total movement is from 30 to 80, which is an addition of 50.
- Calculation:
\[
30 + 50 = 80
\]
- Expressing in Tens:
- 80 is equivalent to 8 tens.
- Answer:
\[
30 + 50 = 80 = 8 \text{ tens}
\]

Final Answers:

1. \( 20 + 30 = 50 = 5 \text{ tens} \)
2. \( 40 + 20 = 60 = 6 \text{ tens} \)
3. \( 30 + 50 = 80 = 8 \text{ tens} \)

Boxed Final Answer:

\[
\boxed{50, 5, 20, 60, 6, 30, 50, 80, 8}
\]