Draw a Birthday Bar Graph

What You Do:

1. Have your child record his classmates' birthdays from the teacher or each of his classmates.
2. Once the data has been collected, he is ready to create the bar graph. Take white poster board and lay it in front of him lengthwise (the long side should be horizontal, and the shorter side vertical).
3. Then, have your child make one vertical line and one horizontal line with a marker, leaving a two inch border on each side, starting in the bottom left corner. The vertical line is called the y-axis and the horizontal is called the x-axis.
4. Next, ask him to make small vertical marks every two inches along the horizontal line until he has made 12 marks.
5. Instruct him to write the name of each month or its abbreviation under each vertical mark. Write the title "Birth Months" underneath the months.
6. Have him make small marks two inches apart along the vertical line. Number the marks 1–10 on the left-hand side of the line. (It is unlikely that more than 10 children will have the same birth month, but if that's the case, he can make the chart higher.)
7. Then, write the title "Number of Students" vertically beside the numbers.
8. Now he's ready to begin graphing the recorded data, starting with January. For example, if there are two children born in January, have him take the ruler and make a vertical line from January up to the number 2. Then, have him form the line into a bar at least an inch thick so that it's visible from a distance.
9. Repeat the above step with the rest of the months. If a month does not have any birthdays, have him make a small, but visible line across the horizontal x-axis. Ask him to place a zero on the left hand side of the horizontal or x-axis.
10. Encourage him to give the graph a title at the top. For example, Room 14's Birthday Graph. If he wishes, he can add some decorations around the graph.
11. When the graph is complete, he can finish off this activity by analyzing it. Have him answer the following questions:
    • According to the graph, how many total students are in the class?
    • Are the results suprising? (Often, the birthdays are not evenly dispersed as one would expect. He may find that there's a month with many birthdays, and a month with very few or no birthdays.)
    • How many children were born in February?
    • How many children were born in April?
    • Which month(s) has the most birthdays?
    • Which month(s) has the least birthdays?
    • Find the difference between the month with the most birthdays and the month with the least amount of birthdays.
    • How many children total have January and June birthdays?
    • How many more (or less) birthdays does August have than December?