2000 x 200 = 400000
When using front-end estimation, we add or subtract the front digits, and then adjust for a more accurate estimation by estimating the sum of the digits to the right of the decimal point.
It is 15.
30
When using front-end estimation, first you add the front-end digits. Then adjust by estimating the sum of the remaining digits. Then add the two values
by adding or subtracting the values of the digits in the front place
2.0638
By using front end estimation, the numbers that you start of with have only one significant digit. It is, therefore, nonsense to have an answer with loads of significant digits.
Using Estimation to Solve Problems. ... Estimating means finding an answer that is an approximate answer. When estimating, your answer must make sense, but it does not need to be exact. You need to find an answer that is reasonable.
500 + 400 = 900
10 + 1 + 4 = 15
8 + 11 = 19
8000 + 3000 = 11000