Austin bought his seven friends each a robot. Each robot costs $8.75. He was charged $7.22 total for tax. He left with $11.53 in change. How much did Austin start with? Let's think first. Chain of thought:
First we need to find the total amount for the robots. 7 robots * $8.75 per robot = $61.25 in total. Now we need to add in the tax $61.25 for the robots + $7.22 for tax = $68.47 total spent in store. Now to find what was the beginning amount we take the $68.47 total spent in - store + $11.53 in change = $80 to start.
Therefore, the answer is 80.