Convert 30% to a decimal by dividing by 100 = 0.30
Multiply by the cost of the helmet, $50
50 x 0.30 = $15, the amount of the discount.
50-15 = $35, the sale price of the helmet.
For the sales tax, again, convert to a decimal by dividing by 100 = 0.06
35 x 0.06 = 2.10, the amount of sales tax
$35 + $2.10 = $37.10, total cost with tax