[Question]Donny has $78 in his piggy bank. If Donny buys a kite for $8 and a frisbee for $9. How much money does Donny have left?
[Answer]Donny has 78 - 8 = 70 after paying for the kite. He has 70 - 9 = $61 left after buying the frisbee as well as the kite. The answer is 61.

[Question]Steven has 4 times as many shirts as Andrew. Andrew has 6 times as many shirts as Brian. If Brian has 3 shirts, how many does Steven have?
[Answer]Andrew has 6 * 3 = 18 shirts. So, Steven has 4 * 18 = 72 shirts. The answer is 72.

[Question]James has 3 fish tanks. 1 of the tanks has 20 fish in it and the other two have twice as many fish each as the first. How many total fish do they have?
[Answer]The second and third tank each have 20 * 2 = 40 fish. So in total there are 20 + 40 * 2 = 100 fish. The answer is 100.

[Question]Jean has 3 grandchildren. She buys each grandkid 2 cards a year and puts $80 in each card. How much does she give away to grandchildren a year?
[Answer]

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Each grandchild gets 2 * 80 = $160 a year. So that means they get a total of 3 * 160 = $480. The answer is 480.