Bonita evaluated 56 × 123 and got an answer of 73. how can you tell that her answer is wrong?

Let's estimate
56 is like 60
123 is like 100 (not reall, but close)
60 times 100=6000 which is nowhere close to 73
also 123 is bigger than 73 and 56 is greater than 1 so therefor even if i was 123 times 3, the answer is still greater tahn 73, and since 56 is greater tahn 3, we know that 56 times 123 is way way bigger than 73

estiation