math Did I do it right?
posted by Bart on .
Use frontend estimation to find the value of the expression. I do not understand (without adjustment)
687  239 (without adjustment)
is this right?
600 + 200= 800 + 126=926

If your problem is 687  239, it makes sense to me to do it this way:
700 = 200 = 500 
Correction:
700  200 = 500 
Right it was subtraction. So what does "without adjustment" mean?

I'm not a math teacher  but I assume you don't need to adjust for the small differences between your estimated numbers and the actual numbers.
This site may explain it.
http://mathforum.org/library/drmath/view/65415.html 
Thank you