Question

$46 shoes, 2.9% tax what is the total cost

Answer 1

You do 2.9% * $46 , which is 0.029 * $49 and you get $1.42

Answer 2

The total cost is 100%(the price of the shoes) + 2.9%(tax). That totals 102.9% which when expressed as a decimal is 1.029. Therefore, the total cost is 46 x 1.029 = 47.334, as it is currency it would be rounded up to $47.35.
Hope it helps :)