H

half hour

An amount of time equal to 30 minutes. One-half of an hour (60 minutes) is 30 minutes.

half-dollar

A coin worth 50 cents (50¢); half of one dollar.

halves

2 parts of a whole that are the same size. The singular of halves is half. (See also fair share and one-half.)

halving

Making something half as big; subtracting half of a number (12 − 6 = 6) or dividing a number by two (12 ÷ 2 = 6).

height

The distance from top to bottom; how tall something is.

hexagon

A two-dimensional (2-D) shape having 6 sides and 6 corners.

horizontal axis

The horizontal axis goes side-to-side or left to right on a graph. (See also vertical axis.)

hour

A unit of time equal to 60 minutes.

hour hand

The small hand on a clock that shows the hour. It takes 60 minutes for the hour hand to travel once around the clock.

hundreds

1. The whole numbers that are three digits long (100–999).

2. The third place or column from the right is called the hundreds place. For example, in the number 215, the 2 represents 2 hundreds.