HANCOCK COUNTY ELEMENTARY SCHOOL

Menu

**PLACE VALUE:**

9-digit numbers can be written in this manner:

Example: Write 392,819,375 as words:

**Three hundred ninety-two million, eight hundred nineteen thousand, three hundred seventy-five**

In a 9-digit number, each digit is in a different place and has a different value. The place value will help identify the particular place such as hundred millions, ten millions, millions, hundred millions, ten thousands, thousands, hundreds, tens or ones and its value.

Example: In 162,584,903

the digit 6 is in the

**ten millions**place

the digit 6 stands for 60 million, or 60,000,000

the value of the digit 6 is 60,000,000

**COMPARING NUMBERS:**

Start comparing the 2 numbers for the ten thousands place.

- When one number is bigger than the other, use the words greater than to describe it.
- When one number is smaller than the other, use the words smaller than to describe it.

**MORE THAN AND LESS THAN**

Substitute the words more than with an addition sign (+).

Example: What is 20,000 more than 58,324?

20,000 + 58,324 = 78,324

Similarly, substitute the words less than with a subtraction sign (-).

Example: What is 9,000 less than 12,685?

12,685 - 9,000 = 3,685

**ORDER AND PATTERN**

When arranging a set of numbers in order,

- determine if the order must begin with the largest or the smallest,
- compare the place value of the numbers,
- arrange the numbers in the correct order.

- determine if the number pattern is in a increasing or decreasing order,
- find the difference between 2 consecutive numbers,
- apply the difference to find the unknown number.

**ROUNDING:**

Rounding is to express a number to its nearest ten, hundred, thousand, or million

Symbol: approximation sign (~)

Step 1: Identify the digit to observe.

Step 2: If the digit is less than 5, round down to a lower number.

Step 3: If the digit is equal to or more than 5, round up to a higher number.

Examples: 936 ~ 940 (when rounded off to the nearest ten)

~ 900 (when rounded off to the nearest hundred)

**ESTIMATION**

Estimation gives an approximate calucation when performaing addition, subtraction, multiplication, or division.

**Estimation in addition/subtraction**

Step 1: Round the addends/minuends/subtrahends to the nearest ten or hundred.

Step 2: Add the rounded addends/minuends/subtrahends.

Examples: 56 + 93 ~ 60 + 90 = 150

81 - 25 ~ 80 - 30 = 50

**Estimation in multiplication**

Step 1: Round the multiplicand to the nearest ten or hundred.

Step 2: Multiply the rounded multiplicand by the multiplier.

Example: 68 X 5 ~ 70 X 5 = 350

**Estimation in divison**

Step 1: Round the dividend to the nearest number for easy division

Step 2: Divide the rounded dividend by the division to get the final answer.

Example 731 9 ~ 720 9 = 80

A FACTOR is a number that can be divided into another number exactly.

dividend factor = quotient

A factor can also be a multiplicand or multiplier

factor X factor = product

Example: The factgors of 14 are 1, 2, 7, and 14

A multiple is obtained by multiplying a number by another number.

factor x factor = multiple

Example: The multiples of 5 are 5, 10, 15, 20, 25, 30, .......

Powered by