Answer:
5200 - 2677 - 543 = 1980
1980 + 3220 = 5200
We have 5200 total and we are subtracting 2677 and 543. 2677 + 543 = 3220. So 5200 - 3220 is 1980 just like 5200 - 2677 - 543. And we know to check with adding by doing 1980 + the ammoument we subtracted which is 3220. SO, 1980 + 3220 = 5200.