Position the ruler on the paper to draw a 10-inch horizontal line. Alternatively, use a yardstick and draw a longer line on a chalkboard for classroom purposes.
Draw short vertical lines at both ends of the lines. Label the vertical line on the left end of the horizontal line "0" and label the vertical line on the right end of the horizontal line "1."
Draw another vertical line halfway between the left and right vertical lines. Draw two more vertical lines halfway between the left line and the center line and halfway between the right line and the center line. This divides the number line into quarters or four equal parts.
Label the center line "2/4," the second line from the left "1/4" and the second line from the right "3/4." Add an additional label to the center line and explain that "1/2" and "2/4" are equivalent fractions.
Add additional vertical lines halfway between each existing pair of vertical lines. Label the new second line from the left "1/8," the next new line from the left "3/8," the next new line "5/8" and the last new line "7/8." Add additional labels to the existing lines in order from left to right: "2/8," "4/8" and "6/8."
Erase all vertical lines except the first and last lines. Draw two vertical lines to divide the number line into three equal parts. Label the second line from the left "1/3" and the next line "2/3." Add additional vertical lines halfway between each existing pair of vertical lines. Label the new second line from the left "1/6," the next new line "3/6" and the last new line "5/6." Add additional labels to the existing lines in order from left to right: "2/6" and "4/6."
Erase all vertical lines except the first and last lines. Label the first line "0" and the last line "10." Draw nine additional vertical lines at even intervals along the horizontal line to divide it evenly -- every inch for a paper number line and perhaps every 3 inches to 4 inches for a chalkboard number line. Label the first line from the left "1" and each line moving to the right in sequential whole numerical order.
Add additional vertical lines to divide the distance between each pair of lines in half. Label the first new line from the left "1/2," the second new line "1 1/2" and so on in sequential order along the entire line. Add additional vertical lines to divide the number line into smaller fractions, if you desire.