The tutor continues with algebra tiles. Tutoring math, you see them especially in grades 9 or 10.

I began discussing algebra tiles here. Recall that they are meant to model numbers, variables, and operations you can perform to them. Recalling the foil method, we’ll take a look at how algebra tiles can be used to “show” it.

Example: Show (x+6)(x-2) with algebra tiles.

Solution: We know by the foil method that the answer is x^2+4x-12.

With algebra tiles, the layout is rows and columns. We might, for instance, display x+6 across the top, and x-2 down the left, as follows:

The result of the multiplication is in the “body” of the table. We see one large white square (which means +x^2), six white rectangles (+6x), then two black rectangles (-2x), and finally, twelve small black squares (-12). The two black rectangles cancel out two of the white ones, leaving four. The result is x^2 +4x -12, as we knew from foil.

Some people find foil quite difficult, while this visual method is easier for them. Once they’re used to it, they hopefully become comfortable with how it translates to foil.

I’ll be saying more about algebra tiles in future posts:)

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.