Original price $45.00; markdown 22%

First convert 22 to decimal form. You do this by dividing the percent by 100.
22 / 100 = .22

Then multiply the dollar amount by the percentage in decimal form.

$45 * .22 = $9.9

So 22% of $45 is $9.9.

Then you subtract $9.9 from $45.

$45 - $9.9 = $35.1

The first digit is in the middle school 100s place