PSAT Math : PSAT Mathematics
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Example Questions
Example Question #1 : Decimals
Write 0.45 as a fraction.
.45 is equivalent to 45 out of 100, or 
Divide both the numerator and denominator by 5 to simplify the fraction:
Example Question #5 : Decimals
Express as a fraction:
Let 
Then
and
Subtract:
Example Question #1 : How To Multiply Decimals
45.728 x 3.2 = ?
14.63296
14632.96
146329.6
1463.296
146.3296
146.3296
Multiply the numbers out in long format, then move the decimal point over the total number of decimal points in the two numbers (3 in the first, 1 in the second, so 4 total):
45.728 * 3.2 = 91456
91456 + 1371840 = 1,463,296 → 146.3296
Or just count the decimal points in the answer and make sure it's 4.
Example Question #2 : Decimals
At the farmer's market, oranges are $0.30 each, apples are $0.25 each, bananas are $0.40 each, and tomatoes are $0.60 each. If Scott buys 3 oranges, 7 apples, 4 bananas, and 8 tomatoes, how much does he spend?
$6.80
$10.40
$7.75
$9.05
$11.40
$9.05
To find out how much Scott spends, we need to multiply the quantity of each fruit by its price and add them all up.
3 * $0.30 + 7 * $0.25 + 4 * $0.40 + 8 * $0.60 = $9.05
Example Question #1 : How To Multiply Decimals
If 
We can approximate the value of y pretty quickly:
y ≈ 1(0.50)(52) = 26
Since y = 0.25x = (1/4)x we know that x = 4y ≈ 4(26) = 104
Example Question #73 : Decimals
0.6
0.06
6
0.0006
0.006
0.006
It's much easier to work with whole numbers, so we'll ignore the decimals for the first step: 5 x 12 = 60
Now look at the decimals. To add them back in, think of 60 as 60.0. Now move the decimal point four places to the left: 0.5 x 0.012 = .0060 = .006
Example Question #13 : Decimals
At the store, green fabric costs $4.53 a yard. How much does 3.8 yards of green fabric cost? (Round to two decimal places.)
$17.12
$17.22
$17.31
$17.13
$17.21
$17.21
This is a simple multiplication problem involving decimals. Simply multiply 4.53 by 3.8:
Now, round to the nearest two decimal places, giving an answer of 17.21.
Example Question #4 : How To Multiply Decimals
Find the product. Round to the nearest hundredths place.
The hundredths place is the position two places to the right of the decimal. Our product is 
Example Question #424 : Arithmetic
simplify: 0.2 ÷ 0.04
0.2 ÷ 0.04 <- easiest way to approach is to move the decimal to the right (the same amount of spaces on each side) so that the decimal disappears
since 0.04 has 2 spaces and 0.2 only has 1, move the decimal 2 spaces to the right on each side
0.2 ÷ 0.04 = 20 ÷ 4 = 5
Example Question #502 : Arithmetic
If the cost of 20 equally priced pencils cost $5.80, then at the same rate what is the greatest number of pencils you can purchase for $50?
172.41
172
150
173
200
172
Remeber for this problem that you cannot spend more than $50. First find the price of each pencil by 5.80/20 = 29 cents. And then use this to do 50/0.29 = 172.41. So the greatest number of pencils you can purchase for $50 is 172 pencils.
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