Explain how you used a mental math strategy to solve 41 + 170.
(One example)
I know that it would be easier to add 40 to 170. 40+170=210. I didn't add enough so I need to add one more!
100
Draw a picture of this equation:
100-43=?
Solve for the missing part.
Check your picture!
57.
100
Round 27,983 to the nearest ten thousand.
30,000
200
What is 600-177?
423
200
What is 43,988 + 45,056?
89,044
200
Explain how you used a mental math strategy to solve
635-59.
I used counting on!
59+1=60
60+40=100
100+500=600
600+35=635
1+40+500+35=576
200
Dau earned $29 from mowing lawns and $17 for doing his chores. What is the total amount that Dau earned?
1. Create a drawing and equation to help you.
Check your drawing!
29 + 17 = ?
Dau earned $46 total.
200
Estimate the sum: 7,502 + 2,187=?
Rounding to the Nearest Thousand: 8,000 + 2,000 = 10,000
Rounding to the Nearest Hundred: 7,500 + 2,100 = 9,600
Rounding to the Nearest Tens: 7,500 + 2,190 = 9,690
300
Ally's team scored 73 points in the first half of a basketball game. Her team won the game by a score of 124 to 103. How many points did her team score in the second half?
51
300
What is 80 + 960 + 4 + 1,986?
3,030
300
Nyasia has collected 24,823 box tops in her life time. Chase has collected 18,931 box tops. How many more box tops does Nyasia have? Show your work.
Nyasia has 5,892 box tops.
300
Sydney has 55 minutes to complete two quick checks and one review sheet. If Sydney finishes her quick checks in 32 minutes, how many minutes does she have left to finish her review sheet? Draw a picture and solve.
Check your picture!
Sydney has 23 minutes.
300
Sue was directed to round 63,493 to the nearest ten thousand. She came up with 63,000. What is the error in her thinking?
She rounded to the nearest thousand, not the nearest ten thousands place!
If you round to the nearest ten thousands place, the digits that follow will be zeros.
400
Sam scored 10,830 points playing a video game. Josh scored 9,645 points. How many more points did Sam score than Josh?
1,185 more points.
400
What is 27,987 + 2,096 + 15,098 + 7,945?
53,126
400
A crayon company makes 17,491 green crayons and 15,739 red crayons. How many more green crayons are made than red crayons?
1752 more green crayons.
400
Mike was building a model airplane. The kit came with 214 pieces. 34 were yellow and 89 were blue. So far he has used 125 of the pieces. How many pieces are left?
Draw a picture and write an equation to help you solve.
Check your picture!
214-125 = ?
89 pieces are left.
400
There are 2,822 kids in one school and 436 kids in another school. Kuol thinks that estimating to the nearest thousand will give him the most reasonable estimate of the total kids. Jonas thinks that estimating to the nearest hundred will give him the most reasonable estimate of the total kids. Who do you think is right? Why?
Rounding to the nearest hundred gives the most reasonable estimate, because if you rounded 436 to the nearest thousand, you would round it to 0.
500
The fourth grade has collected 324 box tops in September, 372 in October, and 125 in November. Their goal is to collect 1,350 by December. How many more do they need to collect?
529 left to collect!
500
Mark added 429 + 699 + 314 and got 950. Is this sum reasonable? Why/Why not?
No! If you round the numbers to the nearest hundred and add the estimate, you get 1,400.
500
Mrs. Hunting wants to bake 6 dozen cookies for her graduation party. She has already eaten 4 cookies. She has made 19 cookies. How many does she have left to make?
6 dozen cookies = 72 cookies.
72-19=53 cookies left to make
500
Monica has 274 pixie sticks. 117 of them are cherry flavored. 69 are lemon flavored. How many are orange flavored?
Draw a picture to help you solve!
Check your picture!
88 are orange flavored.
500
Anna is a world traveler! Last week she flew the following distances in miles: 2,020; 1,358; 952; 2,258; and 1,888.
Which of the following is a good estimate of the miles Anna flew last week?
A 6,000 mi B 6,800 mi C 7,000 mi D 8,000 mi