posted by Anonymous on .
Without finding the exact answer, select which of the following numbers is the best estimate of each sum or difference of 2/3, 0, or 2/3. of the problem 1/9 + 2/5 - 1/3 - 3/4.
How would you solve this as an estimation?
"each sum or difference of 2/3, 0, or -2/3."
There is probably a typo where the minus sign was missed out in the last choice.
If that is the case, then you should be able to find the right one when you see that the answer is negative:
1/9 + 2/5 - 1/3 - 3/4
=(1/9 - 1/3) + (2/5 - 3/4)
by rearranging the terms (associative property of addition)
Both groups of terms in parentheses are negative, so which choice would you take?