Billions, Approximations, & Estimations
In the number 6,397,912, what is the value of the digit 7?
7,000
List the first five multiples of 8.
8, 16, 21, 32, 40
What is a prime number?
A number that can only be divided by 2 factors, 1 and itself.
What is 250,000 x 400?
100,000,000
5,600 ÷ 10 =
560
Write the number in words: 2,000,607,900.
two billion, six hundred seven thousand, nine hundred.
What is the smallest common multiple of 3 and 8.
3, 6, 9, 12, 15, 18, 21, 24, 27
8, 16, 24, 32
24
What is a prime number between 10 and 20?
11, 13, 17
Estimate the value.
625 x 23
600 x 20 = 12,000
1,432,000 ÷ 4000 =
358
Round 997,234 to the nearest thousand.
997,000
The smallest common multiple of 2, 3, and 8 is?
2: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26
3: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33
8: 8, 16, 24
24
List the composite numbers between 47 and 53.
48, 49, 50, 51, 52
764 x 32 ≈ _____ x ______
= 24,000
800 x 30
Estimate the value.
349 ÷ 21 ≈ _____ ÷ ______
= ________
349 ÷ 21 ≈ 300 ÷ 20
= 15
Estimate the value of the following.
157,600 ÷ 4 ≈ _______ ÷ 4
= _______
157,600 ÷ 4 ≈ 160,000 ÷ 4
= 40,000
Of all the common factors of 24 and 32, which is the greatest?
8
Rewrite using exponents:
81 x 20 = ______ x ______ x _______
22 x 34 x 5
There are 115 apartments in a building. Each apartment costs $526,000. Estimate the total cost of all the apartments.
$60,000,000 or $50,000,000
Make a quick estimate of $47,215 x $794.
$48,000 x $800
$60,000
A number was rounded to 360,000. Which of the following numbers could it have been?
A. 354,962
B. 367,152
C. 358,342
C. 358,342
What is the sum of the second multiple of 7 and the sixth multiple?
56
Show the prime factors of 108 using exponents.
22 x 33