U N D E R S TA N D I N G P L AC E VA LU E

ROUNDING WHOLE NUMBERS

PLACE VALUE VS. FACE VALUE

• What is the difference between place value and face value?

WRITE THIS DOWN• Digits have face value, i.e. 0, 1, 2, 3, 4, 5, 6, 7, 8,

9• Digits make numbers.

• Numbers have place value.• With numbers we establish a decimal place.

• Why are they called Roman Numerals and not Roman Numbers?

ESTABLISHING PLACE VALUE

Millions

HundredThousand

s

TenThousan

ds

Thousands

Hundreds Tens Ones

1 2 3 4 5 7 9

WRITE THIS DOWNWhere does the decimal go for this number?

1234579

How do we say this number?

One million two hundred thirty four thousand five hundred seventy nine.

NUMBERS VS. DIGITS

1 2 3 4 5 7 9

Tell me the number.

Tell me the digit.

One Million

Two hundred Thousand

Thirty Thousand

Four Thousand

Five Hundred

Seventy

One Two Three Four Five Seven

ROUNDING WHOLE NUMBERS

Here’s an example problem. Don’t worry about the answer.

Since we are looking for the nearest hundred, the floor of 682 is 600 and the ceiling of 682 is 700.

To determine which number is closest we must look at the digit in the following place, the tens place in this case. If the digit is greater than 5 then you rise, if it’s less than four then you floor.

ROUNDING WHOLE NUMBERS

700

First, we look at the number in the hundreds place. This means the number is between 600 and 700.

Second, we look at the digit in the following place. Since this digit is greater than five, we rise.

This makes the nearest hundred 700.

ROUNDING WHOLE NUMBERS

500

First, we look at the number in the hundreds place. This means the number is between 500 and 600.

Second, we look at the digit in the following place. Since this digit is less than four, we floor.

This makes the nearest hundred 500.

ROUNDING WHOLE NUMBERS

How does the process change when we round to the nearest tens? What place determines if we rise or floor? What digit determines if we rise or floor?

What is the floor of this number?80

What is the ceiling of this number?90

What is the nearest ten?80

ROUNDING WHOLE NUMBERS

What is the floor of this number?530

What is the ceiling of this number?540

What is the nearest ten?540

ROUNDING WHOLE NUMBERS

ROUNDING WHOLE NUMBERS

ROUNDING WHOLE NUMBERS

ROUNDING WHOLE NUMBERS

ROUNDING WHOLE NUMBERS

ROUNDING WHOLE NUMBERS

ROUNDING WHOLE NUMBERS

EXIT TICKET

• Using ALEKS, send me a message with the subject “Rounding Whole Numbers Exit Ticket”

• In the body explain the process of rounding whole numbers, and the difference between rounding to the nearest ten, hundred and thousand.

The quiz for this lesson is available in ALEKS under WHOLE NUMBERS – ROUNDING.