| A | B |
|---|
| Acute Angle | An angle that is less than a right angle. |
| Algorithmn | A method of calculation. |
| Angle | An opening between two intersecting lines. |
| Average | A middle amount; found by dividing the sum of the numbers by the number of numbers. |
| Century | One hundred years. |
| Circumference | The distance around a circle; the curved line that bounds a circle. |
| Common | In reference to numbers, the same number, as in common factor, common multiple, and common denominator. |
| Compare | Determine whether one number is greater than another number or whether the two numbers are equal. |
| Decade | Ten years. |
| Decimal places | Places to the right of a decimal point. |
| Decimal point | A period used to make the separation of the ones' place and the tenths' place. |
| Denominator | The bottom number of a fraction. |
| Diameter | The distance across a circle. |
| Difference | The result of subtraction. |
| Digit | Any one of the ten symbols 0,1,2,3,4,5,6,7,8,9. |
| Dividend | In division, the number being divided. |
| Divisible | Able to be divided without a remainder; for example 6 is divisible by 1,2,3, and 6. |
| Divisor | In division, the number by which another number is divided. |
| Equivalent | Of the same value; for example, 2/4 is equivalent to 1/2 or 2/4=1/2. |
| Estimate | To roughly determine a size or value; to calculate approximately using rounded numbers. |
| Factor | A number being multiplied. |
| Fraction | Part of a whole. |
| Horizontal | Level; parallel with the horizon. |
| Improper fraction | A fraction with the numerator equal to or greater than the denominator; a fraction that is equal to or greater than 1. |
| Intersecting lines | Lines that cross; lines with a common point. |
| Invert | Exchange the numerator and the denominator of a fraction. |
| Minus sign | Symbol for subtraction; also used for negative numbers. |
| Mixed number | A number made up of a whole number and a fraction. |
| Negative | Opposite of positive; a number less than zero. |
| Noon | Midday. |
| Numeral | A written symbol for a number. |
| Numerator | The top number of a fraction |
| Oblique | Slanted. |
| Obtuse Angle | An angle greater than a right angle but less than a straight angle. |
| Parallel lines | Lines that stay the same distance apart. |
| Perimeter | The distance around a closed plane figure. |
| Perpendicular lines | Lines which intersect and form right angles. |
| Place value | That value of a digit determined by the position of the digit within the numeral. |
| Plane figure | A shape, drawn on a flat surface, that has length and width, but no thickness. |
| Plus sign | Symbol for addition. |
| Polygon | Straigth-sided closed plane figure. |
| Prime | A number divisible by only 1 and itself. |
| Product | The result of multiplying. |
| Proper fraction | A fraction with a numerator that is less than the denominator. |
| Quadrilateral | Any four-sided polygon. |
| Quotient | The result of division. |
| Radius | The distance from the center of a circle to the outside edge of the circle. |
| Rectangle | A four-sided polygon having four right angles. |
| Reduce | To form an equivalent fraction with a smaller numerator and denominator. |
| Remainder | What is left after subtraction; also, since division serves to repeat subraction, what is left after division. |
| Right angle | A square angle, often marked with a square. |
| Segment | Part of a line. |
| Sequence | A list of numbers following a rule or plan. |
| Solve | Find a missing value in an equation; find a solution to a problem. |
| Sphere | A smooth geometric solid shaped like a ball. |
| Square | A rectangle, all of whose sides are the same length. |
| Straight angle | An angle which forms a straight line. |
| Sum | The result of addition. |
| Tally mark | A mark to keep track of counting. |
| Times sign | Symbol for multiplication. |
| Triangle | A polygon with three angles and three sides. |
| Vertical | Straight up and down; perpendicular to horizontal. |
| Whole numbers | All the numbers in the sequence 0,1,2,3.... |
| Reciprocal | A fraction resulting from inverting a fraction. |
