Texas Instruments TI-73 7

Using the TI-73: A Guide for Teachers

Number Sense

3.Give students a set time period to trade cookie “bites” (slices) with each other. Tell them they must trade equal-sized pieces, so they will need to know what fractional parts are equal to each other.

Example A ½ slice may be traded for two ¼ slices.

At the end of the trade time, each student should still have a whole cookie, but now it is made of a variety of cookie ingredients.

4.Discuss the results with your students. Ask:

Why did some have a whole cookie, and some did not?

What kinds of trades could they have made to end up with a whole cookie?

5.Use the TI-73 to verify equivalent fraction trades and to count or add up fractions to see if they equal a whole cookie.

Example 1 If a student traded ¼ for 3/12, the student would enter

Y = Q " - t # # # to = b # to Done b

[ = Y Z b

Example 2 If a student traded for ¼, ½, and 3/12, the student would enter

Y = Q " \ Y = Z " \ [ = Y Z b

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If a 1 is displayed on the right-hand side of the screen, the 2 fractions are equivalent. If a 0 is displayed, they are not equivalent fractions.

If a 1 is displayed on the right-hand side of the screen, the student knows the pieces add up to a whole cookie.