Mental Math
54+34
88
Write the missing number
7+1=1+?
7
Round to the nearest tens to estimate
58+43
60+40=100
The team scored 38 points in the first half and 24 points in the second half. How many points did they score all together? Check if your answer is reasonable.
38+24= 62 points
40+20=60
Yes it is reasonable.
Use mental math to solve.
38+42
80
42+29
71
(5+3)+9=8+?
9
Round to the nearest hundred to estimate
242+359
200+300=500
Miss McGrath is driving 33 miles to school everyday. She has already driven 16 miles, how many more miles does she have left? Check to see if your answer is reasonable.
33-16= 17 more miles
30-20=10
Yes it is reasonable.
Show how you use mental math to find 73-17.
73-17
17+3=20
73-20= 53
53+3=56
38+27
65
What property of addition is this?
7+0=7
Identity of addition
Round to the nearest hundreds to estimate
313+478
300+500=800
There are 60 students going on the field trip. 28 of the students are from Dr. Bolton's class. The rest of the class is from Mrs. Sandova-Garza's class. How many students are in Mrs. Sandova-Garza's class? Check to see if your answer is reasonable?
60-28=32
60-30=30
Yes it is reasonable.
Mr. Williams wants to sell 45 raffle tickets for a fundraiser. He has sold 26 tickets so far. Which number sentence shows a way to find how many more raffle tickets Mr. Williams needs to sell?
A- *-26=45
B- 45-*=20
C-26+45=*
D- 26+*=45
38-14
24
Andrea has 15 donuts and Moises has 8. How many more donuts does Andrea have than Moises.
6 more donuts
Round to the nearest ten to estimate
677-421
680-420=260
California has 67 counties. California has 27 more counties than Nevada. How many counties does Nevada have? Check for reasonableness.
67-27=47
70-30=40
Yes it is reasonable.
Write the missing number in the number sentence below.
6+(3+12)=6+*
15
66-15
51
Adrian invited 13 people to his birthday party, and only 9 have shown up. How many people have yet to arrive?
4 people
Round to the nearest hundred to estimate
478-267
500-300=200
Mrs. Carter drove 365 miles on Monday and 204 miles on Tuesday. Is 261 miles a reasonable answer for how many more miles Mrs. Carter drove on Monday than on Tuesday?
360-200=160
400-200=200
No, it is not a reasonable answer
Which number sentence is an example of the Commutative Property of Addition?
A- 47+0=47
B- 35 +(3+47)=(35+3)+47
C- 3+47=47+3
D- 35+0=35