PSAT Math : How to order decimals from least to greatest or from greatest to least

Study concepts, example questions & explanations for PSAT Math

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Example Questions

Example Question #1 : How To Order Decimals From Least To Greatest Or From Greatest To Least

Order the following decimals in order from least to greatest:

2.1, 6.9, 4.8, 5.2, 8.5

Possible Answers:

2.1, 4.8, 5.2, 6.9, 8.5

8.5, 6.9, 5.2, 4.8, 2.1

6.9, 4.8, 8.5, 5.2, 2.1

2.1, 5.2, 8.5, 4.8, 6.9

Correct answer:

2.1, 4.8, 5.2, 6.9, 8.5

Explanation:

Look at the ones place first, ignoring the decimal. The order from greatest to least is 2, 4, 5, 6, and 8. Because none of the numbers in the ones place are the same, it doesn't matter what the decimal will be on these numbers- the order will remain the same. The order is 2.1, 4.8, 5.2, 6.9, 8.5.

Example Question #2 : How To Order Decimals From Least To Greatest Or From Greatest To Least

In the number 5,783.2935, what is the digit in the hundredths place?

Possible Answers:

\dpi{100} 8\(\displaystyle \dpi{100} 8\)

\dpi{100} 3\(\displaystyle \dpi{100} 3\)

\dpi{100} 7\(\displaystyle \dpi{100} 7\)

\dpi{100} 5\(\displaystyle \dpi{100} 5\)

\dpi{100} 9\(\displaystyle \dpi{100} 9\)

Correct answer:

\dpi{100} 9\(\displaystyle \dpi{100} 9\)

Explanation:

The digit in the hundredths place is the one two decimal places to the right of the decimal. That digit is 9. Do not confuse the hundredths with the hundreds place, which is three spaces to the left of the decimal.

The answer is 9.

Example Question #1 : How To Order Decimals From Least To Greatest Or From Greatest To Least

Which of these decimals are the greatest?

\(\displaystyle 0.1,\ 0.015,\ 0.201,\ 0.2,\ 0.0900\)

Possible Answers:

\(\displaystyle 0.0900\)

\(\displaystyle 0.201\)

\(\displaystyle 0.2\)

\(\displaystyle 0.1\)

\(\displaystyle 0.015\)

Correct answer:

\(\displaystyle 0.201\)

Explanation:

look at the first decimal place; 0.2 and 0.201 are the largest.

0.2 = 0.200 and 0.201 > 0.200

0.201 is the greatest given decimal.

Example Question #3 : How To Order Decimals From Least To Greatest Or From Greatest To Least

Which of the following is the greatest in value?

Possible Answers:

\(\displaystyle \frac{9}{4}\)

\(\displaystyle 2.5\)

\(\displaystyle \frac{8}{3}\)

\(\displaystyle \frac{5}{2}\)

\(\displaystyle 2.556\)

Correct answer:

\(\displaystyle \frac{8}{3}\)

Explanation:

Turn the fractions into decimals to easily compare them. You can do this quickly on your calculator.

\dpi{100} \small \frac{8}{3}\(\displaystyle \dpi{100} \small \frac{8}{3}\) is approximately 2.667, so this is the largest number.

Example Question #4 : How To Order Decimals From Least To Greatest Or From Greatest To Least

Which of these decimals has the least value?

Possible Answers:

\(\displaystyle 0.00012\)

\(\displaystyle 0.10000001\)

\(\displaystyle 0.0001000\)

\(\displaystyle 0.001\)

\(\displaystyle 1.0001000\)

Correct answer:

\(\displaystyle 0.0001000\)

Explanation:

Trailing zeros at the end of a decimal do not increase or decrease the value of a given decimal. However, zeros that appear after the decimal point and precede a non-zero number decrease the value of the number.

Example Question #1 : How To Order Decimals From Least To Greatest Or From Greatest To Least

Menu

Five friends go to a coffee shop, the menu for which is above. Each has a coupon that is good for one dollar off the price of a butter croissant with the purchase of a large drink, or fifty cents off the price of a butter croissant with the purchase of a small drink.

Mick buys one large iced coffee and one butter croissant.

Keith buys one small iced coffee and one butter croissant.

Bill buys one large cappucino and one butter croissant.

Charlie buys one small cappucino and one butter croissant.

Brian buys two butter croissants.

Who will pay the most, if everyone who can use his coupon does?

Possible Answers:

Keith

Mick

Charlie

Bill

Brian

Correct answer:

Bill

Explanation:

Mick orders a large drink, so he uses his coupon to save a dollar off his croissant. He will pay

\(\displaystyle \$ 3.49 + \$2.29 - \$1.00 = \$4.78\)

Bill orders a large drink, so he uses his coupon to save a dollar off his croissant. He will pay

\(\displaystyle \$ 3.89 + \$2.29 - \$1.00 = \$5.18\)

Keith orders a small drink, so he uses his coupon to save fifty cents off his croissant. He will pay

\(\displaystyle \$ 2.49 + \$2.29 - \$0.50 = \$4.28\)

Charlie orders a small drink, so he uses his coupon to save fifty cents off his croissant. He will pay

\(\displaystyle \$ 2.99 + \$2.29 - \$0.50 = \$4.78\)

Brian does not buy a coffee, so he will not use his coupon. He will pay full price for both croissants, which will be

\(\displaystyle \$2.29 \times 2 = \$4.58\)

Bill pays the most.

Example Question #1 : How To Order Decimals From Least To Greatest Or From Greatest To Least

What is the median of the following numbers: \(\displaystyle 3.45\), \(\displaystyle 2.74\), \(\displaystyle 3.33\), \(\displaystyle 3.89\), and \(\displaystyle 3.56\)?

Possible Answers:

\(\displaystyle 3.45\)

\(\displaystyle 3.33\)

\(\displaystyle 3.56\)

\(\displaystyle 3.89\)

\(\displaystyle 2.74\)

Correct answer:

\(\displaystyle 3.45\)

Explanation:

The median of a given set of numbers is the number that occurs precisely in the middle of all the numbers when they are put in numerical order. Thus, in order to find the median of this set of numbers, you must first put then in order from least to greatest, then find the number in the middle (the third number, in this set of five).

Numerical order for these numbers is:

2.74, 3,33, 3.45, 3.56, 3.89

Thus, the median is 3.45.

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