Math worksheet for adding two-digit and three-digit numbers using open number lines.

To solve the addition problems using a number line, we will follow these steps:

1. Identify the starting point on the number line.
2. Determine the length of the jump based on the second number in the addition problem.
3. Move along the number line by the length of the jump.
4. Find the endpoint, which is the sum of the two numbers.

Let's solve each problem step by step.

---

Problem 1: \( 223 + 132 \)

- Starting Point: 223
- Jump Length: 132
- Number Line Movement:
- From 223, move 100 to reach 323.
- From 323, move 30 to reach 353.
- From 353, move 2 to reach 355.
- Sum: \( 223 + 132 = 355 \)

Answer: \( \boxed{355} \)

---

Problem 2: \( 428 + 403 \)

- Starting Point: 428
- Jump Length: 403
- Number Line Movement:
- From 428, move 400 to reach 828.
- From 828, move 3 to reach 831.
- Sum: \( 428 + 403 = 831 \)

Answer: \( \boxed{831} \)

---

Problem 3: \( 647 + 320 \)

- Starting Point: 647
- Jump Length: 320
- Number Line Movement:
- From 647, move 300 to reach 947.
- From 947, move 20 to reach 967.
- Sum: \( 647 + 320 = 967 \)

Answer: \( \boxed{967} \)

---

Problem 4: \( 744 + 224 \)

- Starting Point: 744
- Jump Length: 224
- Number Line Movement:
- From 744, move 200 to reach 944.
- From 944, move 20 to reach 964.
- From 964, move 4 to reach 968.
- Sum: \( 744 + 224 = 968 \)

Answer: \( \boxed{968} \)

---

Problem 5: \( 310 + 552 \)

- Starting Point: 310
- Jump Length: 552
- Number Line Movement:
- From 310, move 500 to reach 810.
- From 810, move 50 to reach 860.
- From 860, move 2 to reach 862.
- Sum: \( 310 + 552 = 862 \)

Answer: \( \boxed{862} \)

---

Problem 6: \( 622 + 203 \)

- Starting Point: 622
- Jump Length: 203
- Number Line Movement:
- From 622, move 200 to reach 822.
- From 822, move 3 to reach 825.
- Sum: \( 622 + 203 = 825 \)

Answer: \( \boxed{825} \)

---

Final Answers

1. \( 223 + 132 = \boxed{355} \)
2. \( 428 + 403 = \boxed{831} \)
3. \( 647 + 320 = \boxed{967} \)
4. \( 744 + 224 = \boxed{968} \)
5. \( 310 + 552 = \boxed{862} \)
6. \( 622 + 203 = \boxed{825} \)

---

Boxed Final Answer:
\[
\boxed{355, 831, 967, 968, 862, 825}
\]