Wednesday, September 26, 2007

Estimating Adding and Subtracting by Rounding and Front-End Estimation

When we estimate we round to the biggest place value number. The rest of the digits become zeros. Then we add.



When we estimate we round to the biggest place value number. The rest of the digits become zeroes. Then we subtract.



When you do front-end estimation you keep the biggest place value digit and turn the rest to zero. You do not round. Then add or subtract. By Ellie and Rob






When you are estimating and adding or subtacting numbers with a different amount of digits, you round to the biggest place value spot for each number. By Max