To find the total including tax, multiply the price of the item times 1.07. For example if the item is $1, the total with tax will be $1 x 1.07 or $1.07, which is the same as $1 for the item plus the tax of 7% x $1, or .07 x $1, which is $.07.
If the item is $10, the total with tax will be $10 x 1.07 or $10.70 which is the same as $10 plus tax of ($10 x .07), which equals .70. $10 + .7 = $10.70