Final answer:
To calculate how much money you have left after spending $83.40 on food, subtract $83.40 from $278.
Step-by-step explanation:
To calculate how much money you have left after spending $83.40 on food, you need to subtract the amount spent from the initial amount. In this case, you have $278 and you spent $83.40.
To calculate the remaining amount, you subtract $83.40 from $278: $278 - $83.40 = $194.60.
So, after spending $83.40 on food, you will have $194.60 left.