{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Setting up cross

# Setting up cross - ( writtentext.Forinstance .95\$,...

This preview shows pages 1–2. Sign up to view the full content.

Picture 1 Setting up cross-proportions (cross-multiplications) A cross-proportion is a mathematical expression of a problem that you are usually given in a form of a written text. For instance: If a dozen of donuts costs 4.95\$, then how much does one donut cost? Let’s simplify: if 12 donuts cost 4.95 \$ then 1 donut costs x Notice how “donut” lies underneath “donuts”. “Donuts” can be considered to be the “ units “ of the goods you are buying. Consequently, you can expect the “\$” units to accompany the result for x. Let’s simplify the above even further, by losing the “if” and “then”, and replacing the “cost(s)” by a dash ( not a minus sign): 12 donuts - 4.95 \$ 1 donut - x The above can be written into a four compartment box: 12 donuts 4.95 \$ 1 donut x To solve for x, multiply the numbers in the two compartments that lie daigonally across from each other by each other, and divide the result by the number in the compartment that lies diagonally across from the one in which the x is located.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}