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• Index 441-454

Box 8–3 Building on Spreadsheet Experiences

Jo, like several of her 14- and 15-year-old peers, had some previous experience with algebra. But she disliked mathematics and had performed very poorly on the algebra test given at the beginning of the study. She viewed algebraic symbols as no more than letters of the alphabet whose numerical values corresponded to their position in the alphabet. During a four-month study (with one lesson per week), Jo learned how to use a spreadsheet to solve various kinds of word problems. At the end of the study, she was given the following problem to solve (with no computer available):

One hundred chocolates were distributed to three groups of children. The second group received four times as many chocolates as the first group. The third group received 10 chocolates more than the second group. How many chocolates did the first, second, and third groups receive?

Jo drew a spreadsheet on paper and showed in her written solution how the spreadsheet code was beginning to play a role in her thinking processes. Interviewed subsequently, she was asked,

“If we call this cell x, what could you write down for the number of chocolates in the other groups?”

She wrote the following, which shows that she was now able to represent the problem using the literal symbols of algebra (note that the syntax of many spreadsheets requires the entry of an equal sign before the algebraic expression):

 =x =x×4 =x×4+10

SOURCE: Sutherland, 1993, p. 22. Used by permission of Micromath.

values of the variable.44 For example, given the situation that a plumbing company charges \$42 per hour plus \$35 for the service call, students are asked to find the cost of a 3-hour service call and of a 4.5-hour service call. This inductive-support strategy has students provide an arithmetic representation for the problem before being asked to give the algebraic representation. Such an intelligent tutor has been made part of an experimental ninth-grade algebra curriculum that focuses on the mathematical analysis of realistic situations.

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