Representing 7/8 on the number line:
To represent 7/8 on the number line, we need to follow these steps:

1. Draw a horizontal line to represent the number line.

2. Mark a point at the center of the line to represent zero.

3. Mark a point to the right of zero to represent one.

4. Divide the distance between zero and one into eight equal parts.

5. Mark the seventh part to the right of zero.

6. Join the seventh point to zero with a straight line.

7. Label the seventh point as 7/8.

Representing -3/5 on the number line:
To represent -3/5 on the number line, we need to follow these steps:

1. Draw a horizontal line to represent the number line.

2. Mark a point at the center of the line to represent zero.

3. Mark a point to the right of zero to represent one.

4. Mark a point to the left of zero to represent -1.

5. Divide the distance between zero and -1 into five equal parts.

6. Mark the third part to the left of zero.

7. Join the third point to zero with a straight line.

8. Label the third point as -3/5.

In conclusion, representing fractions on a number line is an effective way to visualize them and understand their relative positions. By following the above steps, we can accurately represent 7/8 and -3/5 on the number line.