Budget

According to the graph, by about how much did the U. S. federal budget increase from 1992 to 2001?

Approaches

Add the negative (200 Ð 300 = –100 or180 Ð 300 = –120)

Work backward (–300 – 200 = –500)

Does the negative result mean that the budget has decreased since 1992?

Write backward but without a negative (300 Ð 200 = 100 or 300 Ð 180 = 120)

Subtract visually, or by subtracting a negative (480 = 300 + 180 or 500 = 300 + 200 or 480 = 300 Ð (Ð180))

Use percentages: 200/–300 is about –67%.

"By how much" often does refer to a percentage, but not if one number is negative.

Call the result "trillions" instead of "billions."

Discuss reasons for change (Reagan-Bush vs Clinton)

Discuss non-constant dollars

Add up deficits to get large value ("500 trillion")

Your experience

Have you used this problem with a class and seen approaches other than(or more specific than) those mentioned above? Or do you have other comments or criticisms or stories? If so, please tell us!

Last updated 30 November, 2004