3rd grade math
posted by Anonymous on .
front end estimation to estimate the sum...like..436+517= ~~~~~~also we have some problems that say use rounding to estimate the sum...like..236+710=....DO WE DO BOTH OF THESE THE SAME WAY??? solve then estimate??? my child has been out from school for a few days sick and missed this. Thanks!

front end estimation: 436+517=400+500=900
rounding: 236+710= 200+700=900
front end estimation:
* Add the digits of the two highest place values
* Insert zeros for the other place values
* Example 1: 4496 + 3745 is estimated to be 8100 by front end estimation (i.e. 4400 + 3700).
* Example 2: 4496 + 745 is estimated to be 5100 by front end estimation (i.e. 4400 + 700).
rounding:
* Rounding makes numbers that are easier to work with in your head.
* Rounded numbers are only approximate.
* An exact answer generally can not be obtained using rounded numbers.
* Use rounding to get a answer that is close but that does not have to be exact.
How to round numbers
* Make the numbers that end in 1 through 4 into the next lower number that ends in 0. For example 74 rounded to the nearest ten would be 70.
* Numbers that end in a digit of 5 or more should be rounded up to the next even ten. The number 88 rounded to the nearest ten would be 90. 
attn(happy face)thank you!!

ashton broke apart a number into 30+7. what number did she start with?

use any methond to eastimate each difference

use any method estimate 667651