Question: 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?
Find the solution. 
Answer: 
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.