NL Grade 3 Math flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Place value

The value of a digit based on its position in a number. In 352, the 3 is in the hundreds place, so it means 300.

Rounding to nearest ten

Look at the ones digit. If it is 5 or more, round up to the next ten. If it is less than 5, round down. Example: 47 rounds to 50.

Regrouping

When adding or subtracting, exchange 10 ones for 1 ten, or 1 ten for 10 ones. This is used when a column sum is 10 or more, or when subtracting a larger digit from a smaller one.

Multiplication

Repeated addition of equal groups. 4 × 3 means 4 groups of 3, which equals 12.

Fraction

A number that represents equal parts of a whole. The denominator shows the total number of equal parts; the numerator shows how many parts are taken. Example: 3/4 means 3 out of 4 equal parts.

Even number

A number that ends in 0, 2, 4, 6, or 8. It can be divided into two equal whole numbers. Example: 8 is even because 8 ÷ 2 = 4.

Odd number

A number that ends in 1, 3, 5, 7, or 9. It cannot be divided into two equal whole numbers. Example: 7 is odd.

Comparing numbers

Compare digits from left to right. The number with the greater digit in the first place where they differ is larger. Example: 472 > 468 because 7 > 6 in the tens place.

Money

In dollars and cents, $1.00 equals 100 cents. To add or subtract money, line up the decimal points and regroup as with whole numbers.

Repeating pattern

A pattern with a core that repeats over and over. Example: red, blue, red, blue, ... The core is red, blue.

Growing pattern

A pattern where the number of elements increases by a constant amount each time. Example: 2, 4, 6, 8, ... increases by 2.

Number sequence rule

The operation that changes one term to the next. To find it, compare consecutive terms. The rule may be add, subtract, multiply, or divide by a constant.

Input/output table

A table that shows how a rule changes an input number into an output number. Example: rule is input + 5 = output. If input is 3, output is 8.

Equality

The equals sign means "is the same as." An equation like 5 + 3 = 8 is balanced because both sides have the same value.

Missing number

A number that makes an equation true. In 7 + ? = 12, subtract 7 from 12 to find the missing number: 5.

Pattern in a table

A consistent change in the output column as the input increases by 1. Example: input 1,2,3 gives output 3,6,9; the rule is multiply by 3.

Polygon

A closed 2-D shape with straight sides. Examples: triangle (3 sides), quadrilateral (4 sides), pentagon (5 sides), hexagon (6 sides).

Cube

A 3-D solid with 6 square faces, 12 edges, and 8 vertices. All edges are equal length.

Line of symmetry

A line that divides a shape into two matching halves. A square has 4 lines of symmetry.

Congruent shapes

Shapes that have the same size and shape. They may be rotated or flipped but still match exactly.

Perimeter

The distance around a shape. Add the lengths of all sides. Example: a rectangle with sides 3 cm and 5 cm has perimeter 16 cm.

Area

The number of square units needed to cover a shape. For a rectangle, area = length × width.

Right angle

An angle that measures 90°. It looks like the corner of a square. An angle smaller than a right angle is acute; larger is obtuse.

Ordered pair

Two numbers (x, y) used to locate a point on a grid. The first number tells how far right; the second tells how far up.

Bar graph

A graph that uses bars to show the number of items in each category. The height of each bar shows the count; the scale tells what each grid line represents.

Pictograph

A graph that uses pictures to show data. Each picture stands for a number of items, shown in the key. Example: key = 2 means each picture represents 2 items.

Line plot

A graph that shows data using X marks above a number line. The number of Xs above a value shows how many times that value occurs.

Mode

The number that appears most often in a data set. Example: in 2, 3, 3, 5, the mode is 3.

Range

The difference between the greatest and least values in a data set. Example: for 4, 7, 9, range = 9 − 4 = 5.

Probability

A number from 0 to 1 that describes how likely an event is. 0 means impossible; 1 means certain.

Fair game

A game in which each player has the same chance of winning. If outcomes are equally likely, probability = number of favorable outcomes ÷ total number of outcomes.

Scale on a graph

The number that each grid line or picture represents. It helps read the value of bars or pictures correctly.