**Math:** the systematic treatment of magnitude, relationships between figures and forms, and relations between quantities expressed symbolically.

Also, mathematical procedures, operations, or properties.

## Dictionary : Letter Y

**Y Axis**

The line on a graph that runs vertically (up-down) through zero.

**Y Coordinate**

The vertical value in a pair of coordinates. How far up or down the point is.

**Y Intercept**

The point where a line or curve crosses the y-axis of a graph.

**Yard**

A unit of length (or distance) in US units equal to 3 feet or 36 inches.

**Year**

The period of time it takes Earth to go once around the Sun.

There are 365 days in a normal year and 366 days in a leap year.

There are 12 Months in a year.

There are a little over 52 weeks in a year.

The first day of the year is 1st January, and the last day is 31st December.

**Yield**

How much money an investment makes, usually per year as a percent of the total investment.

**Yocto-**

A prefix meaning one-septillionth (1/1,000,000,000,000,000,000,000,000 or 10^{-24})

The same as multiplying by 10^{-24} (which is 0.000 000 000 000 000 000 000 001)

**Yotta-**

A prefix meaning one septillion (1,000,000,000,000,000,000,000,000 or 10^{24})

The same as multiplying by 10^{24}