Download 6th Grade Math Vocabulary

6th Grade Math
Chapter 1
Decimals
Lesson 1-1
Understanding
Whole Numbers
Definition
Facts/Characteristics
A number written in
digits and place value
The place of the digit 5 in
254 is tens. The value of
5 is 50
Vocabulary
Word
Standard
form
524 is standard form
1,286 is standard form
Examples
It is not the only
way to write a number
Non-Examples
Definition
Facts/Characteristics
A sum that shows the
place and value of each
digit of a number
The expanded form shows
the value of each digit
Vocabulary
Word
Expanded
form
1,000 + 200 + 80 + 6
is the expanded form of
1286
Examples
“1 thousand 2 hundred 86”
is the short word form
Non-Examples
Definition
Facts/Characteristics
A number in standard form
is separated into groups
of three digits using commas.
Each of these groups is
called a period.
Each period in a number
written in standard form has
between 1 and 3 digits
Vocabulary
Word
Period
A period in math is
A
Examples
not a dot at the end of a
sentence.
Non-Examples
Lesson 1-2
Reading and Writing
Decimals
Decimal Place Value
Decimals in Expanded Form

Recall the definition of expanded form
Example: write 1.893 in expanded form
1 + 0.8 + 0.09 + 0.003
Decimals in Word Form

Write 23.876 in word form
23.876
And
eight hundred seventy
six thousandths
Twenty-three
Lesson 1-3
Comparing and
Ordering Decimals
Ordering Decimals on a Number
Line
Compare and order 0.47, 0.34, 0.21, 0.58
Compare Decimals Using Place
Value
Use <,>, or = to compare 4.28 and 4.8
These digits are the same
4.28
4.80 write a zero at the end of the

number so each number has the
same number of decimal places
Tenths digit is different, 2 < 8.

4.28 < 4.8
Compare digits starting with the
highest place value
Lesson 1-4
Estimating With
Decimals
Definition
Facts/Characteristics
Numbers that are easy
to compute mentally
Also called “friendly
numbers” as mental
calculations are easy
Vocabulary
Word
3.67 x 42.5
4 x 40 = 160
3.67 x 42.5 ≈ 160
Examples
Compatible
Numbers
10.93 + 3.25
11 + 3
10.93 + 3.25 ≈ 14
Non-Examples
Definition
Facts/Characteristics
Add the “front-end
Gives a higher estimate
digits,” estimate the
as involves the cents, less
sum of the remaining likely to be short of money
Vocabulary
Word
Front-End
Estimation
$3.98
6.49 then look
9.08 at the cents
+3.47 adjust the estimate
21
21 + about $2 = $23
Examples
$3.98 + $6.49
4 + 7 = 11
$3.98 + $6.49 ≈ $11.00
Non-Examples
Lesson 1-5
Adding and
Subtracting
Decimals
Commutative Property of
Addition

Changing the order of the addends
does not change the sum.
5.78 + 9.3 = 9.3 + 5.78
Associative Property of Addition

Changing the grouping of the addends
does not change the sum
(3.2 + 8) + 4 = 3.2 +( 8 + 4)
Identity Property of Addition

The sum of 0 and any number is that
number
4.5 + 0 = 0 + 4.5 = 4.5
Finding Decimal Sums

Line up the decimal points!!!
Add: 3.842
2.450 write zeros so that all
+1.300 decimals have the same
7.592
number of digits to the
right of the decimal point
Finding Decimal Differences

Line up the decimal points!!
7 10
Subtract: 68.0
- 51.8
16.2
rename as 7 and 10 tenths
Estimate answers first then check for
reasonableness!
Whole Numbers - Decimals
Subtract: 60-23.68
Estimate an answer
59.109 10
Solve: 60.00
- 23.68
n
36.32
write a decimal point and two zeros
rename as 59 and 10 tenths, then rename as 9
and10 hundredths
Lesson 1-7
Multiplying Decimals
Commutative Property of
Multiplication

Changing the order of the factors does
not change the product.
5.78 x 9.3 = 9.3 x 5.78
Associative Property of
Multiplication

Changing the grouping of the factors
does not change the product
(3.2 x 8) x 4 = 3.2 x ( 8 x 4)
Identity Property of Multiplication

The product of 1 and any number is
that number
4.5 x 1 = 1 x 4.5 = 4.5
Whole Number X Decimal
0.25
x 5
1.25
two decimal places
0 decimal places
Add the number of decimal places in
the factors to find the number of
decimal places in the product.
Decimal X Decimal
0.25
x .015
125
+025
.00375
two decimal places
three decimal places
move the decimal point five places to
………………………………………………..the left
Add the number of decimal places in the
factors to find the number of decimal
places in the product.
Lesson 1-8
Multiplying and
Dividing Decimals by
10, 100, and 1,000
Multiplying by 10, 100 and 1,000

Move decimal point to the right as
many places as there are zeros
3.5 x 10 = 35
3.5 x 100 = 350
3.5 x 1,000 = 3500
0.67 x 10 = 6.7
0.67 x 100 = 67
0.67 x 1,000=670
Pattern: think about direction decimal
point moves and the number of spaces
Dividing by 10, 100 and 1,000

Move decimal point to the left as many
places as there are zeros
3500 ÷ 10 = 350
3500 ÷ 100 = 35
3500 ÷ 1,000 = 3.5
0.67 ÷ 10 = .067
0.67 ÷ 100 =.0067
0.67 ÷ 1,000=.000670
Pattern: think about direction decimal point
moves and the number of spaces
Lesson 1-9
Dividing Decimals
Definition
Facts/Characteristics
A decimal that stops All terminating decimals
or terminates, as in a
can be written as a
remainder of 0
fraction
Vocabulary
Word
Terminating
Decimals
Examples
Non-Examples
Dividing by a Whole Number

Divide as with whole numbers. Place
the decimal point in the quotient above
the decimal point in the dividend.
Definition
Repeats the same
digit or group of
digits
Facts/Characteristics
A bar, or line, is drawn
over the digits that repeat
Vocabulary
Word
Repeating
Decimals
Examples
Non-Examples
Dividing by a Whole Number
Decimal ÷ Decimal

Multiply both the dividend and the
divisor by the same number, (multiple
of 10), so the divisor becomes a whole
number.
Lesson 1-10
Order of Operations
Using Order of Operations
Please Excuse My Dear
Aunt Sally
Do all operations within parentheses
first
 Multiply and divide in order from left to
right
 Add and subtract in order from left to
right
