Estimation
Addition
Subtraction
Rounding
Random!
100
8,467 pencils were dropped on the floor during the 2021 school year. 3,697 were dropped on the floor in 2020. Which is the best estimate of how many more pencils were dropped in 2021 than in 2020?
a. 3,000
b. 4,000
c. 5,000
d, 11,000
b. 4,000
Because 8,467 rounds to 8,000 and 3,697 would round to 4,000. 8,000 - 4,000 is 4,000.
100
394 + 254
648
100
488 - 24
464
100
Round 457 to the nearest 10
460
100
I am the smallest 2-digit number that rounds to 100 when rounded to the nearest ten. What number am I?
95
200
Third graders at Bush Hill Elementary School read a total of 3,959 books last year. They want to read about 875 more books this year. Estimate how many books should they read altogether.
About 5,000 books
200
In a village, there are 2,520 lions and 1,840 giraffes. What is the population of lions and giraffes combined?
4,360
200
4,000 - 365
3,635
200
Round 4,651 to the nearest 100
4,700
200
All 3 of my digits are the same. When I am rounded to the nearest hundred, I become 800. What number am I?
777
300
Jimmy and Maria are saving up for a new television and Nintendo Switch. They found a television at Best Buy for $265 and the Nintendo Switch for $317. Jimmy says they need to save about $500 to buy the television and the Nintendo Switch. Maria says they need to save about $600. Who do you agree with? Why?
Maria because $265 is about $270 and $317 is about $320. If we estimate, those two added together will be almost $600 ($590). $500 will not be enough.
300
There were 2,325 hockey fans in the arena for the game Friday night. On Saturday there were 3,127 fans that showed up for that game. What was the total number of hockey fans that came to both games?
5,452 hockey fans
300
Ms. Ransom has $94 to spend on Peppy's birthday gifts. She goes to the pet store and spends $65 on a new deluxe memory foam bed and $23 on treats. How much money does Ms. Ransom have left?
$88
$6
$8
$7
$6
300
Round 45,250 to the nearest 1,000
45,000
300
Jack has 326 blue marbles in a jar and 285 red marbles in another jar. Approximately how many marbles does he have in both jars combined? To find the total, ROUND each number to the nearest hundred, then solve.
Approximately 600 marbles
400
Mrs. Duffy bought a Nationals Hockey ticket. The ticket cost $91. She also spent $47 on chicken tenders, popcorn, and drinks. About how much money did Mrs. Duffy spend in all?
Mrs. Duffy spent about $150.
400
1,052 students from New York went on vacation for spring break. At the same time, 3,274 students from California went on vacation. How many students from both states went on vacation for spring break in all?
4,326 students
400
7,928 - 6,342 =
1,583
400
Round 3,599 to the nearest thousand
4,000
400
I am an odd 3-digit number. If you round me to the nearest ten, I become 790. The sum of my digits is 17. What number am I?
791
500
Use estimation to answer the following expression: 27,982 + 12,444
30,000 + 10,000 = 40,000
500
On Earth Day, 3,459 trees were planted along the west coast. On the east coast, 2,725 trees were planted. How many trees were planted all together on Earth Day?
6,184 trees
500
6,000 - 796 =
5,204
500
Round 34,954 to the nearest hundred and thousand.
Hundred: 35,000 Thousand: 35,000
500
What number should go in the box to make the statement true?
23 + 14 + 56 = 56 + 23 +
a. 56
b. 23
c. 14
d. 93
c. 14