WorkKeys Applied Math key terms

The value a digit has because of its position in a number. In 4,702 the 7 means 700, while in 7,240 the 7 means 7,000.

Replacing a number with a nearby, simpler number that has fewer nonzero digits. You look at the next digit to decide whether to round up or stay the same.

Finding an answer that is close enough rather than exact, often by rounding numbers first. It is useful for checking whether a calculated answer is reasonable.

Doing arithmetic in your head without writing out the steps or using a calculator. It helps you spot errors quickly and judge whether a tool's answer makes sense.

A counting number such as 0, 1, 2, or 3, with no fraction or decimal part. Many workplace counts, such as boxes or people, must be whole numbers.

A number written with a decimal point to show parts of a whole, such as 2.75. The digits to the right of the point represent tenths, hundredths, and so on.

A way of writing part of a whole, such as 3/4, meaning 3 of 4 equal parts. Fractions are common in measurements, recipes, and mixing ratios.

A fraction expressed out of 100, written with a % sign. For example, 25% means 25 out of every 100, or one quarter.

The result of adding several values and dividing by how many values there are. It summarizes a group of numbers with a single typical value.

The middle value in a list of numbers arranged from smallest to largest. If there is an even count, it is the average of the two middle values.

The difference between the largest and smallest values in a data set. It shows how spread out the numbers are.

A comparison of two quantities by division, often written as 3:1 or 3 to 1. It tells how much of one thing there is compared with another.

An equation stating that two ratios are equal, such as 2/5 = 8/20. Proportions are used to scale recipes, drawings, and mixes up or down.

A method for solving a proportion by multiplying the top of one side by the bottom of the other. For a/b = c/d, it gives a times d equals b times c.

A ratio that compares quantities with different units, such as miles per hour or cost per box. It describes how one quantity changes with another.

A rate in which the second quantity is exactly one unit, such as 45 miles per 1 gallon. It makes comparing different offers or speeds easy.

The cost of one item or one unit of measure, found by dividing total cost by quantity. It lets you compare packages of different sizes fairly.

A reduction in price, often given as a percent off the regular price. You subtract the discount amount from the original price to find the sale price.

The amount added to a cost to set a selling price, often stated as a percent of cost. It covers expenses and provides profit.

The difference between selling price and cost, often expressed as a percent of the selling price. It measures how much of each sale remains as profit.

A percentage added to the price of goods by a government and collected at purchase. It is calculated on the taxable amount, not on the whole bill when some items are exempt.

Money paid for the use of borrowed money, usually a percent of the amount owed or saved. Simple interest is calculated on the original amount only.

The original amount of money borrowed or invested, before any interest is added. Interest is figured as a percent of this base amount.

An average in which some values count more than others, based on assigned weights. It is used for grades, blended rates, and combining groups of different sizes.

The total distance around the outside edge of a shape, found by adding the lengths of all sides. It is used for fencing, trim, and border materials.

The amount of flat surface a shape covers, measured in square units. For a rectangle it equals length times width.

The amount of space a three-dimensional object occupies, measured in cubic units. For a rectangular box it equals length times width times height.

The distance around a circle, equal to pi times the diameter. It is needed when ordering material to wrap or edge a round object.

The straight-line distance across a circle through its center, equal to twice the radius. It is often used to size pipes, covers, and round tables.

The unit used to measure area, such as a square foot or square meter. One square foot is a square measuring one foot on each side.

The unit used to measure volume, such as a cubic foot or cubic yard. One cubic yard is a cube measuring one yard on each side.

A ratio that changes a measurement from one unit to another without changing the amount, such as 12 inches per 1 foot. Multiplying by it converts the units.

A measurement of length or distance in one direction, such as inches, feet, or meters. It is used for perimeter, distance, and material lengths.

The amount a container can hold, often measured in gallons, liters, or cubic feet. It differs from outside dimensions because walls take up space.

The amount by which a measurement may vary and still be acceptable, often shown as a plus-or-minus range. Parts outside the tolerance must be rejected or reworked.

A stated requirement for size, material, or performance that a product or job must meet. It gives the standard against which work is checked.

A judgment about whether an answer makes sense given the situation and the size of the numbers involved. Checking reasonableness catches errors such as misplaced decimal points.

A pay rate equal to 1.5 times the regular hourly wage, commonly paid for overtime hours. You multiply the regular rate by 1.5, then by the overtime hours.

The relationship between a drawing or model and the real object, such as 1 inch equals 10 feet. It lets you convert measured lengths on a plan to actual distances.