1. Third Grade
Math Vocabulary

2. Addend – any of the numbers that is added. 2 + 3 = 5 addend addend

3. Properties of addition:
Properties of addition: *Identity Property-states that when you add zero to a number, the result is that number Example = 7 *Commutative property of addition- states that you can add two numbers in any order and get the same sum Example = 10 and = 10 *Associative property- states that you can group addends in different ways & still get the same sum Example (2+3)+1 = 2 + (3+1)

4. Place value – the value of each digit in a number, based on the location of the digit.
decimal – a number
with one or more
digits to the right of
of the decimal point.

5. Array – an arrangement of objects in rows and columns.
Factor – a number that is multiplied by another number to find the product.
This array represents 2 X 4 = 8
Product – the answer for a multiplication problem.

6. Properties of Multiplication
Associative property – states that when the grouping of factors is changed, the product remains the same.
Example (3 X 4) X 2 = 3 X (4 X 2)
Commutative property – states that you can two factors in any order and get the same product.
Example 4 X 7 = 28 and 7 X 4 = 28
Identity property – states that the product of any number and one is that number.
Example 5 X 1 = 5
Distributive property – states that multiplying a sum by a number is the same as multiplying each addend by the number, and then adding the products.
Example 3 X (4 + 2) = (3 X 4 ) + (3 X 2)
3 X 6 =
18 = 18

7. Inverse Operations – opposite operations, or operations that undo each other, such as addition and subtraction or multiplication and division.
*subtraction checks addition * multiplication checks division
÷ 7 = 2 because 7 X 2 = 14

8. What is division?
Divide – to separate into equal groups; the
opposite operation of multiplication.
remainder
Dividend – the number that is to be divided
Divisor- the number that divides the dividend.
Remainder – the amount left over when a number cannot be divided evenly.

9. Fraction- a number that names parts of a whole or part of a group.
1/3
Numerator – the part of a fraction above the line, which tells how many parts are being counted.
Denominator – the part of a fraction below the line, which tells how many equal parts there are in the whole or in the group.

10. Triangles
Scalene – a triangle in which no sides are equal.
Isosceles – a triangle in which two sides are equal.
Equilateral – a triangle that has three equal sides.

11. Area – the number of square units needed to cover a flat surface.
Example : You can find area by counting the boxes.
Area = 12
Or you can find area by using a formula.
Area = l x w
Area = 4 x 3

12. Perimeter – is (“The fence around the playground
Perimeter – is (“The fence around the playground!”) the distance around a figure.
You can find perimeter by
counting the outside edges.
Or you can find perimeter by using a formula. P = s + s + s + s
P =
P = 24