Estimation
You can use _______________ to check that an answer is reasonable.
What is estimation?
A factor is...
To multiply a 2 digit number by a 1 digit number you can use a _______________ model or a _________________ model.
What is an array model or an area model?
A number is between 10 and 20. It is also a factor of 24. The number is _____.
What is 12?
A number that has only 2 factors (1 and the number itself.)
What is a prime number?
Use rounding to determine 523+298.
What is 800?
A multiple is...
What is a number that can be divided evenly by another number ?
OR
What is the product of two factors?
(Slide 1)
What is 432?
A train is expecting 252 passengers on a Saturday. If each train car can hold 30 passengers, how many train cars will they need to fit everyone?
What is 9 train cars?
When one number is multiplied by another number, the result is called a _______.
What is a product?
We can use rounding to determine the sum of 280+134.
What is 400?
The factors of 24.
What is
1, 2, 3, 4, 6, 8, 12, 24
Slide 2.
What is 210?
Nevere has 40 pumpkins. If she packs them evenly into 3 boxes, how many does she have left over?
What is 1 pumpkin left over?
List the factors of 45.
What is
1, 45, 3, 15, 5, 9
What is 200? (Answers can vary)
What are the first 5 multiples of 11?
What is 11, 22, 33, 44, 55?
Show 19x8 using an area model. Then find the product.
What is 152?
Sarah has $150 to spend on new video games. She has to choose between two of three options; a ps4 game for $60, a nintendo switch game for $83, and a computer game for $98. Should she buy the ps4 game and the switch game? Or the switch game and the computer game?
What is the ps4 game and the switch game?
Solve using an area model.
39x21
What is 819?
Use estimation to solve 38 ÷ 6.
What is 6?
The least common multiple of 3 and 5.
What is 15?
Solve 45x13 using an area model.
What is 585?
An oven costs three times as much as a toaster. If the toaster costs $13, the total cost of 2 toasters and an oven is ____.
What is $65?
Solve 216 ÷ 12.
What is 216?