Answer:
350
Explanation:
In this situation it seems like we should be rounding to 50 because the numbers work well that way, and it is nice number commonly unsed in these situaltions. So, 645 rounded to the nearentest 50 would be 650. And 273 rounded to the nerent 50 would be 300. Now if we subtract 300 from 650, (650-300) we will get 350.