How do you convert a decimal to a percent, and a percent to a decimal?

To convert a decimal to a percent, multiply by 100 (move the decimal 2 places right) and add %. To convert a percent to a decimal, divide by 100 (move the decimal 2 places left). E.g., 0.35 = 35%; 35% = 0.35.

How do you convert a percent to a fraction?

Write the percent over 100 and simplify. E.g., 40% = 40/100 = 2/5.

What is the decimal and fraction equivalent of 50%, 25%, and 75%?

50% = 0.5 = 1/2; 25% = 0.25 = 1/4; 75% = 0.75 = 3/4.

How do you find a percent of a number (e.g., 'What is 20% of 80')?

Convert the percent to a decimal and multiply: 0.20 × 80 = 16.

How do you calculate a percent increase or decrease?

Percent change = (amount of change ÷ original amount) × 100. Use 'increase' if the value went up and 'decrease' if it went down.

A $50 item is discounted 30%. What is the sale price?

$35. The discount is 0.30 × 50 = $15, so 50 - 15 = $35 (or directly 0.70 × 50 = $35).

How do you find what percent one number is of another (e.g., '15 is what percent of 60')?

Divide the part by the whole and multiply by 100: (15 ÷ 60) × 100 = 25%.

In word problems, what operations do the keywords 'sum', 'difference', 'product', and 'quotient' indicate?

Sum = addition, difference = subtraction, product = multiplication, quotient = division.

When translating words to equations, what do 'is', 'of', and 'per' usually indicate?

'Is' usually means equals (=), 'of' usually means multiply (×), and 'per' usually means divide (÷).

Translate into an equation: 'Five less than twice a number is 11.'

2n - 5 = 11. ('Twice a number' = 2n, 'five less than' subtracts 5, 'is' = equals.)

🇺🇸 National Police Officer Selection Test (NPOST / Stanard & Associates POST) · flashcards

National Police Officer Selection Test (NPOST / Stanard & Associates POST) Mathematics Flashcards

50 question-and-answer cards covering Mathematics as it is examined in National Police Officer Selection Test (NPOST / Stanard & Associates POST). 24 of them are printed below, taken from across the deck — no signup, no paywall on the preview.

50Cards in deck

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15Syllabus topics

~101Chars per answer

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24 sample cards from the Mathematics deck

Sampled from the end of the deck, so these are different cards from the ones shown on the syllabus page.

How do you convert a decimal to a percent, and a percent to a decimal?
To convert a decimal to a percent, multiply by 100 (move the decimal 2 places right) and add %. To convert a percent to a decimal, divide by 100 (move the decimal 2 places left). E.g., 0.35 = 35%; 35% = 0.35.
How do you convert a percent to a fraction?
Write the percent over 100 and simplify. E.g., 40% = 40/100 = 2/5.
What is the decimal and fraction equivalent of 50%, 25%, and 75%?
50% = 0.5 = 1/2; 25% = 0.25 = 1/4; 75% = 0.75 = 3/4.
How do you find a percent of a number (e.g., 'What is 20% of 80')?
Convert the percent to a decimal and multiply: 0.20 × 80 = 16.
How do you calculate a percent increase or decrease?
Percent change = (amount of change ÷ original amount) × 100. Use 'increase' if the value went up and 'decrease' if it went down.
A $50 item is discounted 30%. What is the sale price?
$35. The discount is 0.30 × 50 = $15, so 50 - 15 = $35 (or directly 0.70 × 50 = $35).
How do you find what percent one number is of another (e.g., '15 is what percent of 60')?
Divide the part by the whole and multiply by 100: (15 ÷ 60) × 100 = 25%.
In word problems, what operations do the keywords 'sum', 'difference', 'product', and 'quotient' indicate?
Sum = addition, difference = subtraction, product = multiplication, quotient = division.
When translating words to equations, what do 'is', 'of', and 'per' usually indicate?
'Is' usually means equals (=), 'of' usually means multiply (×), and 'per' usually means divide (÷).
Translate into an equation: 'Five less than twice a number is 11.'
2n - 5 = 11. ('Twice a number' = 2n, 'five less than' subtracts 5, 'is' = equals.)
What is the distance formula relating rate, time, and distance?
Distance = Rate × Time (d = r × t).
How do you solve for rate or time given the distance formula?
Rate = Distance ÷ Time (r = d/t); Time = Distance ÷ Rate (t = d/r).
A car travels 150 miles in 3 hours. What is its average speed?
50 miles per hour. Rate = distance ÷ time = 150 ÷ 3 = 50 mph.
What is a ratio, and what are common ways to write one?
A ratio compares two quantities. It can be written as a to b, a:b, or as the fraction a/b.
What is a proportion, and how do you solve one?
A proportion states that two ratios are equal (a/b = c/d). Solve it by cross-multiplying: a × d = b × c, then solve for the unknown.
If 3 apples cost $1.50, how much do 7 apples cost (set up and solve the proportion)?
$3.50. Set 3/1.50 = 7/x, cross-multiply: 3x = 10.50, so x = $3.50.
How many inches are in a foot, feet in a yard, and ounces in a pound?
12 inches = 1 foot; 3 feet = 1 yard; 16 ounces = 1 pound.
How do you make change correctly (e.g., $20 paid for a $13.45 purchase)?
Subtract the cost from the amount paid: $20.00 - $13.45 = $6.55 in change.
When reading a data table to answer a question, what should you do first?
Identify the correct row and column headings (labels and units) so you locate the exact cell where the needed value intersects, and note units before calculating.
On a bar graph, how do you read the value of a given bar?
Trace from the top of the bar horizontally to the value axis (usually the y-axis) and read the number where it lands, accounting for the scale/interval between gridlines.
What does a line graph best show, and how do you interpret a rising vs. falling line?
A line graph shows change or trends over time. A rising line means the value is increasing; a falling line means it is decreasing; a flat line means no change.
What does a pie (circle) chart represent, and what do all its slices add up to?
A pie chart shows parts of a whole as proportional slices; all slices together represent 100% (or the full total).
How do you calculate the mean (average) of a set of numbers?
Add all the values together and divide by how many values there are. Mean = sum of values ÷ number of values.
How do you find the median, mode, and range of a data set?
Median: order the values and take the middle one (average the two middle values if the count is even). Mode: the value that appears most often. Range: the largest value minus the smallest value.

What this deck covers

The Mathematics deck follows the National Police Officer Selection Test (NPOST / Stanard & Associates POST) Mathematics syllabus — 4 chapters and 15 topics — so questions land on material that is genuinely examinable rather than trivia around it. That works out to roughly 12.5 cards per chapter.

Answers are written to be recallable, not just readable — averaging about 101 characters, which is long enough to carry the reasoning and short enough to say out loud.

A deck like this earns its keep on the second and third pass. Read the syllabus first so you know the shape of the subject, then use the cards to find the specific facts that have not stuck.

Mathematics flashcards FAQ

How many Mathematics flashcards are in this National Police Officer Selection Test (NPOST / Stanard & Associates POST) deck?

50 cards. This page previews 24 of them, sampled evenly across the deck so you can judge the difficulty before installing anything.

Are these National Police Officer Selection Test (NPOST / Stanard & Associates POST) flashcards free?

Yes. The preview here is free to read with no signup, and the full 50-card deck is free inside the Examius app.

What do the Mathematics cards cover?

They follow the National Police Officer Selection Test (NPOST / Stanard & Associates POST) Mathematics syllabus — 4 chapters and 15 topics — so the questions track what is actually examinable.

How should I use these flashcards?

Read the syllabus first so you know the shape of the subject, then drill the deck. Examius schedules each card with spaced repetition, so cards you keep missing come back sooner and ones you know drift further apart.