R.1-Place Values and Names of

NumbersMATH 081

Catherine Conway

Vocabulary

• Place values: the position of the digits in a number that determines the value of that digit.

• Digit: number in the number system.

Place Value of Numbers

Expanded Form of a Number

•We can use the idea of place value to write numbers in expanded form.

•Example: Money

•Write $632 in expanded form.600 + 30 + 2

Writing Numbers in Words

• See table on page 6.

• Write the following numbers in words.

• 56

• 902

• 3,972

• 51,205

Fifty six

Nine hundred twoThree thousand, nine hundred seventy - twoFifty-one thousand, two hundred five

R. 2-Addition with Whole Numbers, and

PerimeterMath 081

Catherine Conway

Adding Whole Numbers

• Add the digits within the same place value

Example: 62 + 23

6 22 3

+58

62 = 6 tens + 2 ones23 = 2 tens + 3 ones+85 = 8 tens + 5 ones

You Try: 175 + 201

Answer: 376

Addition with Carrying• If the sum of the digits with the same place value is

larger than 9 we have to do what is called carrying

Example: 185 + 211 + 106185 = 1 hundred + 8 tens + 5 ones211 = 2 hundreds + 1 ten + 1 one

+

502 = 4 hundreds + 9 tens + 12 ones (1

tens + 2 ones) 10 tens 1 hundreds + 0 tens

106 = 1 hundred + 0 ten + 6 ones

You Try:

•Pg 19 #12, 22, 30, 40, 44

Vocabulary and Properties of Addition

• Sum: If a and b are any two numbers, then the sum of a and b is a + b. To find the sum of two numbers means to add the numbers together.

Addition Property of Zero:If we let a represent any number, then it is always true that

a + 0 = a and 0 + a = a.

Commutative Property of Addition:If a and b are any two numbers, then it is always true that

a + b = b + a.

Associative Property of Addition:If a, b and c are any three numbers, then it is always true that

(a + b) + c = a + (b + c).

Practice:

•Pg 20 # 55, 58, 60, 65

Solving Equations

• The letter n that we will be using is know as a variable and it can represent a certain number based on the equation we are trying to solve.

Example: n + 3 = 9What is this asking you to find?n = 6

6 + 3 = 9

You Try: Solve for n.Pg.20 #67-74

GEOMETRY: Perimeter• A polygon is a closed figure, with at least three sides, in

which each side is a straight line.

h

b s

w

l

The perimeter of a polygon is the sum of the lengths of the sides, and it is denoted with the letter P.

Refer to Example 9 on page 17