When I was in Grade 7 our homeroom/math teacher told the class in a hushed voice, “Don’t cross multiply.” At the time I didn’t understand what he meant, nor did I likely understand what cross multiplication was. Ever since I have occasionally wondered why he would admonish students from using such a useful tool. Cross-multiplication … Continue reading To cross multiply or not cross multiply

# Tag: algebra

# Algebraic Expressions vs Algebraic Equations

Give the algebraic expression that represents the perimeter of the following polygon. Over the last five years working as a tutor I have seen many students struggle with a problem like the one above. To answer it we must remember that the perimeter of any shape can be found by adding up its side-lengths. With side-lengths that … Continue reading Algebraic Expressions vs Algebraic Equations