w
The abbreviation for width in formulas, such as A = l × w.
Wage
Money paid to a worker for their work, often a fixed amount per hour.
Washer
A flat ring: the region between two circles that share the same center, shaped like a metal washer; also called an annulus.
Washer method
A calculus method for finding the volume of a solid with a hole in it, made by rotating a region around an axis: V = π∫(R² − r²) dx.
Wavelength
The distance between two matching points on a wave, such as from one peak to the next. On the graph of a trigonometric function, it is the period.
Weak inequality
An inequality that allows the two sides to be equal, using ≤ (less than or equal to) or ≥ (greater than or equal to). On a number line, its endpoint is a closed dot.
Week
A unit of time equal to 7 days.
Weight
A measure of how heavy an object is, caused by gravity pulling on its mass. It is measured in units such as ounces, pounds or newtons.
Weighted average
An average in which some values count more than others. Multiply each value by its weight, add the results, and divide by the total of the weights; also called a weighted mean.
Whole
All of something, or one complete unit. A whole can be split into equal parts, as in 4/4 = 1 whole.
Whole numbers
The natural numbers together with zero: 0, 1, 2, 3, 4, 5, … They include no fractions, decimals or negative numbers.
Wholesale price
The price a store pays a manufacturer or supplier for goods, before it adds a markup to set the retail price.
Width
The distance across something from side to side. For a rectangle it is usually the shorter side, abbreviated w.
Winding number
The number of times a closed curve travels counterclockwise around a point. Clockwise loops count as negative.
Withdrawal
Money taken out of a bank account. A withdrawal lowers the account balance.
Word form
A way of writing a number using words, such as three hundred forty-two for 342.
Word problem
A math problem told in words. To solve it, you turn the words into numbers and operations.
Work problems
Word problems about jobs done at a steady rate, using work = rate × time. Someone who paints a room in 3 hours paints 1/3 of it each hour.