2. How do I know what kind of
decimal it is?
The name of a decimal is determined by the number
of places to the right of the decimal point
Number of Places Decimal Name Example
1 tenths 0.7
2 hundredths 0.05
3 thousandths 0.016
3. What are mixed decimals?
Mixed decimals are numbers with both whole
numbers and decimals
The name of a whole number is determined by the
number of places to the left of the decimal point
In the number 128.765, 1 is in the hundreds place, 2 is in the
tens place, 8 is in the ones place, 7 is in the tenths place, 6 is
in the hundredths place, and 5 is in the thousandths place
4. How do you read decimals?
To read a decimal correctly, first find the decimal
point
Whole numbers are to the left of the decimal point;
any numbers to the right of a decimal point form a
decimal fraction
Say “and” for the decimal point
The decimal 2164.511 is read as “two thousand, one hundred
sixty-four and five hundred eleven thousandths”
5. Zeros after the decimal point
Writing extra zeros after the decimal point
does not change the value!
The decimals 0.2, 0.20, and 0.200 are
equivalent decimals
6. HERE ARE SOME PRACTICE
PROBLEMS IN WHICH I WILL
WORK THROUGH WITH YOU TO
MAKE SURE THAT YOU
UNDERSTAND THE MAIN
CONCEPTS COVERED.
Practice
7. Exercise 1
Write the decimals.
1. Five thousandths
2. Ninety-four thousandths
3. Three hundred thirty-six and sixty-nine
hundredths
8. Exercise 2
Write each decimal in words.
1. 7884.011
2. 5592.4
3. 4.203
4. 612.250
5. 10.44
9. Exercise 3
In what place (on the place value chart) is the
underlined digit? Write the answer.
1. 1.475
2. 3.763
3. 7780.215
4. 412.407
5. 902.103
10. Exercise 4
Write a decimal that has the same
number.
1. 0.2
2. 5.51
3. 410.6
4. 753.809
12. Essential Question:
How do to add and subtract decimals?
Always line up decimals
Add and subtract like you always do
Bring decimal straight down in your
answers
13. Adding
Examples:
4.55 + 11.3
Put the first number on the
top of the second number
and line up the decimals.
4.55
+ 11.3
You can
add a zero
to help keep
everything
lined up
0
15.85
When adding or
subtracting you
always start
from the right
and work left.
14. 6.44 + 16
When there is
not a decimal
put one
behind the
number.
Line up
the
decimal
6.44
+ 16.
Add a zero
to line up
everything
22.44
0
16. 28 – 15.911
When there is
not a decimal
put one
behind the
number.
28.
-15.911
Add zeros to
line up
everything,
then subtract
000
7 9 9
8
0
.
2
1 9
