FAST Math Grade 3 flashcards

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

Expanded form of 5,208

5,208 written as 5,000 + 200 + 8, showing the value of each digit by its place. The zero in the tens place adds nothing.

Standard form of a number

A number written with digits only, such as 6,431. It is the opposite of expanded form (6,000 + 400 + 30 + 1) and word form.

Rounding 847 to nearest hundred

The answer is 800, because the tens digit is 4, which is less than 5, so the hundreds digit stays and the rest become zeros.

Rounding 1,362 to nearest ten

The answer is 1,360, because the ones digit is 2, which is less than 5, so the tens digit stays the same and the ones digit becomes 0.

Product

The result of a multiplication problem. In 7 × 8 = 56, the product is 56. In 3 groups of 4, the product 12 is the total count.

Factor

A number that is multiplied in a multiplication sentence. In 5 × 6 = 30, both 5 and 6 are factors, and 30 is the product.

Commutative property of multiplication

Changing the order of the factors does not change the product: 4 × 9 = 9 × 4 = 36. The total stays the same.

Distributive property

A factor can be split into parts: 7 × 6 = 7 × 5 + 7 × 1 = 35 + 7 = 42. Multiplying each part and adding gives the same product.

Inverse operations

Operations that undo each other. Addition and subtraction are inverses (8 + 5 = 13, so 13 − 5 = 8), and multiplication and division are inverses.

Missing factor 4 × ? = 32

The missing factor is 8, found by dividing 32 ÷ 4 = 8. Division undoes multiplication, so it reveals the unknown factor.

Division with equal groups

Splitting a total into a given number of equal groups. 18 ÷ 3 = 6 means 18 objects shared into 3 groups gives 6 objects in each group.

Remainder in division

The amount left over when a number does not divide evenly. 17 ÷ 5 = 3 with a remainder of 2, because 5 × 3 = 15 and 17 − 15 = 2.

Multiples of 10 by one digit

Multiply the nonzero digits, then attach the zero: 6 × 30 is 6 × 3 = 18 with a zero added, giving 180. The zero shifts the place value.

Numerator

The top number of a fraction. It tells how many equal parts are being counted or described. In 3/5, the numerator 3 means three parts are counted.

Denominator

The bottom number of a fraction. It tells how many equal parts the whole is divided into. In 3/5, the denominator 5 means five equal parts make the whole.

Unit fraction

A fraction with numerator 1, such as 1/2, 1/4, or 1/8. It names one equal part of a whole, and larger denominators mean smaller parts.

Equivalent fractions

Different fractions that name the same amount. 1/2, 2/4, and 4/8 are equivalent because they cover the same portion of the same whole.

Comparing fractions, same denominator

When denominators match, compare numerators: 5/8 is greater than 3/8 because 5 equal parts is more than 3 of the same-size parts.

Comparing fractions, same numerator

When numerators match, the fraction with the smaller denominator is greater: 1/3 is greater than 1/6 because thirds are larger pieces than sixths.

Fraction on a number line

A point marking a distance from 0. The space between whole numbers is divided into equal parts; 3/4 sits at the third mark when 0 to 1 is split into four parts.

Whole number as a fraction

Any whole number can be written over 1: 4 = 4/1. Also, a fraction like 6/3 equals the whole number 2 because 3 fits into 6 twice.

Fraction greater than one

A fraction whose numerator is larger than its denominator, such as 5/4. It names more than one whole and can be shown as 1 and 1/4.

Perimeter

The total distance around the outside of a figure, found by adding all side lengths. A rectangle 5 by 3 has perimeter 5 + 3 + 5 + 3 = 16.

Area of a rectangle

The number of unit squares that cover a rectangle, found by multiplying length × width. A 6 by 4 rectangle has area 24 square units.

Square unit

A square measuring 1 unit on each side, used to measure area. Area is reported in square units, such as square centimeters or square inches.

Area by decomposing

Splitting an irregular shape into rectangles, finding each area, then adding them. A shape made of a 3×2 and a 4×2 rectangle has area 6 + 8 = 14.

Elapsed time

The amount of time between a start and an end. From 9:40 to 10:15, count 20 minutes to 10:00 and 15 more, giving 35 minutes.

Reading a scaled bar graph

When each bar unit stands for more than one item, multiply. If one square equals 5 books, a bar 4 squares tall shows 4 × 5 = 20 books.

Line plot with fractions

A number line marked with data values, where each X shows one item. If four X marks sit above 1/2, then four items measured 1/2.

Quadrilateral

A closed shape with exactly four straight sides and four corners. Squares, rectangles, trapezoids, and rhombuses are all quadrilaterals.

Rectangle versus square

A rectangle has four right angles with opposite sides equal; a square is a rectangle whose four sides are also all equal in length.

Two-step word problem

A problem needing two operations to solve. Example: 3 boxes of 8 pens plus 5 loose pens is 3 × 8 = 24, then 24 + 5 = 29 pens.