Make a Graph

Hi everyone !!
Here is a link in which you can desing your own graph.


http://nces.ed.gov/nceskids/createagraph/default.aspx?ID=29af9a71627e490aab819a1214f2f4a1

OVERESTIMATES AND UNDERESTIMATES

Overestimate : An overestimate happens when you round up.
Ex:
Pedro has 36 DVD´s of series and 57 DVD´s of movies. If he has 100 spaces, does he have enough for the DVD´s? Round to the nearest ten to estimate the sum.

36 rounds up to 40
+57 rpunds up to 60
-------
100 He has enough spaces

Each addened was rounded up so the estimated sum is greater than the actual sum. It is overestimate.

Underestimate : An underestimate happens when you round down.

Sara was in charge of seating the school show. She has set up 34 seats in the center and 23 seats on each side. She is expecting 70 people. Has she set up enough chairs? Round to the nearest ten to estimate the sum.

34 rounds down to 30
23 rounds down to 20
+23 rounds down to 20
-----
70 seats is the estimated sum.

Each addened ws roundes down, so she estimated the sum, 70, is less than the actual sum. It is an underestimated.

Estimate each sum by rounding to the nearest ten. Then tell whether each estimate is an overestimate or underestimate.

ex: 36+47 : (40+50) we overestimate.

1. 23+44 :
2. 66+87:
3. 98+27: