Mental Addition
34+12=?
46
45-12=?
33
What is 212 rounded to the nearest hundred?
200
Rick has $79 dollars. He saves another $56. Estimate the amount of money he has now.
$80+$60=$140
54+46=?
100
57-34=?
23
550
600
Paul has 72 cards. He gives away 59 cards. About how many does he have left?
70-60=10, about 10 cards
27+49=?
76
82-35=?
47
778
800
The Chess Club has $445 to spend on supplies. The Chess boards cost $176 and the pieces cost $189. Estimate the total cost of boards and pieces. Estimate the amount of money left after buying the two items.
$200+$200=$400
$400-$400=$0
or $450-$400=$50
69+21=?
90
94-79=?
15
994
1,000
Mr. Morris sells 726 oranges on Monday. His wife sells 644 oranges on the same day. About how many more oranges does Mr. Morris sell?
700 oranges-600 oranges=100 oranges
Mr. Morris sold about 100 more oranges