Mental Math
45+10
35
23+45+17=
85
123 + 234=
357
If you have 150 apples and you buy 200 more, how many apples do you have?
350
If 256+123 is 379, then 379-123=?
256
583-100=
483
49+13+15=
77
456 - 128=
328
There are 378 students in a school. If 145 students go home, how many are left?
523
If 150+245 is 395, then 395−245=?
150
679+10=
689
30+20+50=
100
789 + 111
900
A farmer has 245 chickens and buys 156 more. How many chickens does he have now?
401
If 500+375 is 875, then 875−375=?
500
Which digit will change in the number 423 if the number 100 is subtracted.
The 4 in the hundreds place will change to a 5
35+25+65=
125
305 - 240
65
A library has 500 books. If 275 books are checked out, how many books are remaining?
225
Emily thinks 10+14+56 is greater than 56+24+10. Is she correct?
Which digit will change in 623 if the number 10 is subtracted.
The number 2 will change into a 1 to make the number 613
67+10+16=
93
500 + 250
750
Sarah saved $250. If she earns $175 more, how much does she have altogether?
425
Rochelle thinks 573+100 is the same as 773-100. Is she correct?
Yes, because 673=673