NL Grade 3 Math key terms

Any one of the symbols 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 used to write numbers. The position of a digit in a number tells how much it is worth.

The value a digit has because of the position it holds in a number. In 472, the 4 means four hundreds, the 7 means seven tens, and the 2 means two ones.

A written symbol or group of symbols that stands for a number, such as 36 or 205. The number itself is the amount; the numeral is how we write it down.

A number written with digits only, in the usual way, such as 508. This is the everyday way numbers appear on signs, price tags, and pages.

A number broken apart to show the value of each digit, written as an addition sentence. For example, 508 is written as 500 + 0 + 8.

A whole number that can be split into two equal groups with nothing left over, such as 4, 10, or 26. Every even number ends in 0, 2, 4, 6, or 8.

A whole number that cannot be split into two equal groups; one is always left over, such as 3, 7, or 25. Every odd number ends in 1, 3, 5, 7, or 9.

Counting forward or backward by a number larger than one, such as counting by 5s: 5, 10, 15, 20. It builds the patterns used for multiplication and for counting money.

The result of multiplying a whole number by another whole number. The multiples of 4 are 4, 8, 12, 16, and so on, growing without end.

The answer you get when you add two or more numbers together. In 35 + 40 = 75, the sum is 75.

Any one of the numbers that are added together in an addition sentence. In 12 + 8 = 20, both 12 and 8 are addends.

The answer you get when you subtract one number from another. In 90 - 35 = 55, the difference is 55, which is how far apart the two numbers are.

An operation that finds how much is left, or how far apart two numbers are, by taking one amount away from another. It is the opposite, or inverse, of addition.

An operation that undoes another operation. Addition and subtraction undo each other, and multiplication and division undo each other, which helps you check answers.

A group of related number sentences that use the same three numbers. From 3, 4, and 12 you get 3 x 4 = 12, 4 x 3 = 12, 12 / 4 = 3, and 12 / 3 = 4.

The answer you get when you multiply two or more numbers. In 6 x 7 = 42, the product is 42.

Objects arranged in equal rows and equal columns, used to show multiplication. A 3 by 4 array has 3 rows of 4, which shows 3 x 4 = 12.

Groups that each contain the same number of items, such as 5 bags with 4 apples in each bag. Repeated equal groups can be added or multiplied to find a total.

Adding the same number again and again to find a total, such as 4 + 4 + 4 = 12. Repeated addition is the idea that multiplication is built on.

A number that names part of a whole or part of a set, written with a top and bottom number. In 3/4, the whole is split into 4 equal parts and 3 of them are counted.

The top number in a fraction. It tells how many equal parts are being counted or described, as the 3 in 3/4 counts three parts.

The bottom number in a fraction. It tells how many equal parts the whole has been cut into, as the 4 in 3/4 means fourths.

Different fractions that name the same amount, such as 1/2 and 2/4. They cover the same portion of a whole even though the numbers are written differently.

Replacing a number with a nearby, simpler number that is easier to work with. 47 rounds to 50 when rounding to the nearest ten, because 47 is closer to 50 than to 40.

A careful guess about an amount or answer, often made by rounding numbers first. Estimating helps you judge whether an exact answer seems reasonable.

A sequence or arrangement that repeats or grows following a rule. The rule tells you what comes next, such as add 3 each time in 2, 5, 8, 11.

The instruction that explains how a pattern is built, such as add 5 or subtract 2. Once you know the rule, you can continue the pattern in either direction.

An ordered list of numbers or objects that follows a rule. Each item is called a term, and the order matters, so 1, 3, 5 differs from 5, 3, 1.

One single number or object in a sequence. In the sequence 4, 8, 12, 16, the third term is 12.

A pattern in which the numbers or shapes get larger each step, such as 10, 20, 30, 40. The amount added may stay the same or may increase.

A pattern in which the numbers or shapes get smaller each step, such as 50, 45, 40, 35. The amount taken away is the rule of the pattern.

A pattern in which a core group of items repeats over and over, such as red, blue, green, red, blue, green. The repeating part is called the core.

A table that shows pairs of numbers, where each input number is changed by a rule to give an output number. Studying the pairs helps you find the hidden rule.

The idea that the two sides of a number sentence have the same value. In 8 + 4 = 6 + 6, both sides equal 12, so the sentence is true.

A closed flat shape made of straight sides that do not cross. Triangles, squares, pentagons, and hexagons are all polygons.

A corner point where two sides of a shape meet, or where edges of a solid meet. A triangle has three vertices and a cube has eight.

One of the straight line segments that forms the boundary of a flat shape. A hexagon has six sides, and a square has four sides of equal length.

A polygon with exactly four straight sides and four vertices. Squares, rectangles, rhombuses, and trapezoids are all quadrilaterals.

A quadrilateral with four right angles, where opposite sides are equal and parallel. A square is a special rectangle whose four sides are all the same length.

An angle that forms a square corner, measuring exactly 90 degrees. The corners of a book or a square tile are right angles.

A line that divides a shape into two halves that are mirror images of each other. A square has four lines of symmetry, and a circle has many.

Having exactly the same size and the same shape. Two shapes are congruent if one can be placed on the other and they match perfectly.

The total distance around the outside edge of a flat shape. You find it by adding the lengths of all the sides, measured in units such as centimetres.

The amount of flat surface a shape covers, measured in square units such as square centimetres. A rectangle's area equals its length multiplied by its width.

A small cube used as a measuring tool for volume, with each edge one unit long. Counting unit cubes that fill a solid tells you its volume.

Information collected by counting, measuring, or asking questions. Data can be recorded in a table, a tally chart, or a graph so it can be studied.

A table that records data using short marks, with every fifth mark drawn across the previous four to make a group of five. It makes counting results quick and accurate.

The number of times something occurs in a set of data. In a tally chart, the frequency tells how many people chose each option.

A graph that uses bars of different heights or lengths to show how many items are in each category. The taller the bar, the greater the frequency.

A graph that shows data using small pictures or symbols, where each symbol stands for a set number of items. A key explains what each symbol is worth.

The value that appears most often in a set of data. In the set 2, 3, 3, 5, 7, the mode is 3 because it occurs twice.

The difference between the greatest and least values in a set of data. For the set 4, 9, 15, the range is 15 - 4 = 11.

A way of describing how likely an event is to happen, using words such as certain, likely, unlikely, or impossible. It can also be described with a number from 0 to 1.

One possible result of an action or experiment, such as getting tails when a coin is flipped. Listing all outcomes helps you judge how likely each one is.

An outcome that is sure to happen, with no other possibility. If a bag holds only red marbles, pulling out a red marble is certain.

An outcome that cannot happen at all. Rolling a 7 on an ordinary six-sided number cube is impossible.