## Thinking Mathematically (6th Edition)

The number is $360$.
step 1 Let x represent the unknown number in the problem. step 2 "$70\%$ of a number" = $\displaystyle \frac{70}{100}\cdot x=0.7x$ " is $224$" is written as " = $252$" step 3 The equation is $0.7x=252$ step 4 Solve, answer the question. $0.7x=252\qquad/\div 0.7$ $x=\displaystyle \frac{252}{0.7}=\frac{2520}{7}=360$ The number is $360$. step 5 Check the solution in the original wording of the problem. $7$0% of $360, \quad$($\displaystyle \frac{70}{100}\cdot 360=252),$ $...$ is $252$. OK.