Question: Grade this work
1. **Problem:** What fraction would be located at point B on the number line divided into fourths with points A, B, C at 1/4, 1/2, 3/4 respectively.
2. **Solution:** Point B corresponds to the fraction $\frac{1}{2}$.
3. **Problem:** Plot $\frac{1}{3}$ on the number line from 0 to 1.
4. **Solution:** $\frac{1}{3}$ is correctly placed one-third along the number line.
5. **Problem:** Plot the fraction $\frac{2}{7}$ on the number line from 0 to 1.
6. **Solution:** $\frac{2}{7}$ is correctly placed two-sevenths along the number line.
7. **Problem:** Find the difference $693 - 124$.
8. **Solution:**
$$693 - 124 = 569$$
9. **Problem:** Solve $560 + 495$.
10. **Solution:**
$$560 + 495 = 1055$$
11. **Problem:** Solve for $?$ in $489 + ? = 600$.
12. **Solution:**
$$? = 600 - 489$$
$$? = 111$$
**Grading:**
- The fractions and plots are correctly identified and placed.
- The subtraction $693 - 124$ is correctly calculated as $569$.
- The addition $560 + 495$ is correctly calculated as $1055$.
- The missing addend $?$ in $489 + ? = 600$ is correctly found as $111$.
**Final score:** 8/8
All answers are correct and calculations are accurate.