Commutative Property of Addition

a + b = b + a; two numbers can be added in either order without changing the sum.

Commutative Property of Multiplication

a X b = b X a; two numbers can be multiplied in either order without changing the product.

factor

Two or more numbers in a product. 2 X 3 = 6, the factors are 2 and 3.

factor pairs

Two factors of a number. 18 has three factor pairs: 1 and 18; 2 and 9; 3 and 6

product

The answer in a multiplication problem. 2 X 3 = 6, the product is 6.

quotient

The answer in a division problem. 35/ 7 = 5, the quotient is 5.

divisor

The number that divides another number in a division problem. 35/ 7 = 5; the divisor is 7.

dividend

The number in a division problem that is being divided. 35/ 7 = 5; the dividend is 35.

even number

A number (integer- ex: 2, -2) that is divisible by two.

odd number

A number (integer- ex: 3, -3) that is not divisible by two.

prime number

A whole number greater than one that has only two whole-number factors. 2, 3, 5, 7, 9, 11, 13, 15, 17, ...

composite number

A whole number greater than one that has more than two factors. 4 has the factors: 1, 4 and 2.

name-collection box

a diagram used for collecting equivalent names for a number

rectangular array

An arrangement of objects into rows and columns that form a rectangle. All rows and columns must be filled. Each row has the same number of objects. Each column has the same number of objects.

square array

A rectangular array that has an equal number of rows and columns.

number model

A number sentence or expression that models a number story or situation.

3 * 4 = 12 Three boys each had 4 marbles.

3 * 4 = 12 Three boys each had 4 marbles.

factor rainbow

A way to show factor pairs in a list of factors of a number. Can be used to check whether a list of factors is correct.

divisible by

If the larger of 2 counting numbers, divided by the smaller with no reminder, the larger is divisible by the smaller.

divisibility rule

A shortcut for determining whether a counting number is divisible by another counting number without actually doing the division.

turn-around rule for multiplication

A rule for solving addition and multiplication problems based on the Commutative Properties of Multiplication and Addition. For example: if you now that 6** 8= 48, then by the turn-around rule you also know that 8 ** 6 = 48.

remainder

An amount left over when one number is divided by another number

square number

The product of two factors that are the same.

exponential notation

a way to show repeated multiplication by the same factor

exponent

A number that stands for the power, or the number of times the base is to be multiplied.

square root

one of the two equal factors of a number

factor string

A counting number written as a product of two or more of its counting-number factors other than 1. The length of the factor string is the numbers in the string. 2**3**4 is a factor string for 24 with length 3.

prime factorization

A whole number expressed as a product of factors that are all prime numbers