Question

Estimate the product of 51 and 48

Answer 1

51 rounds to 50.
48 rounds to 50.
Now multiply 50 by 50 and you get 2500.
The actual answer of the product of 51 and 48 is 2448.
2500 is pretty close to 2448.

Answer 2

If we where to estimate this answer then we would first need to round both of these numbers to 50 because 51 rounds down to 50 and 48 rounds up to 50 and 50*50=2500.

Enjoy!=)