Ratios, proportions, and algebraic thinking for sixth grade students.
If \( \frac{a}{b} = \frac{c}{x} \), then \( x = \frac{b \times c}{a} \).
\[x = \frac{b \times c}{a}\]
If 4 pens cost $12, how much do 7 pens cost? Set up 4/12 = 7/x and solve for x.
A model car is built at a 1:24 scale. If the real car is 12 feet long, the model is 0.5 feet (6 inches).
You can solve for unknowns in proportions using cross-multiplication.