Topic 12 Lesson 1

Topic 12

Understand and Compare Decimal

Lesson 12-1
Fractions and

Decimals

Objective: Today, we
will relate fractions

and decimals with
denominators of

10 and 100.

Decimals are another way to write parts of
a whole. However, unlike fractions that can
be divided in any number of pieces,
decimals show the whole is divided into 10
or 100 pieces. Decimals can also show a
whole divided into 1,000 or 10,000 or even
100,000 pieces, but we will only focus on
10 and 100 right now.

This whole is divided
into 10 equal pieces.
Each piece is one
tenth. We can write
that as a fraction 1/10
or we can write it as a
decimal 0.1

This whole is divided into
100 equal pieces. Each
piece is one hundredth.
We can write that as a
fraction 1/100 or we can
write it as a decimal
0.01

This model shows 37
small pieces out of
100 shaded. That
would be written as
37/100 or 0.37

Again, just as we have place value with
whole numbers, we use place value with

decimals! Take a look.

._____________
TENTH

HUNDREDTH

Hint: One helpful trick is to remember

how many zeros are in 10 and 100.
If you want a decimal to say tenths,
you get ONE place after the decimal.

If you want a decimal to say

hundredths, you get TWO places after

the decimal.

So 0.1 is equal to one TENTH. There is one
place after the decimal. The whole is cut

into ten pieces and you have 1.

0.01 is equal to one HUNDREDTH. There are

two places after the decimal. The whole is
cut into one hundred pieces and you have 1.

0.1 is MORE than 0.01

0.1 is MORE than 0.01

Think about pizzas of the same size.
One is cut into 10 pieces and you get 1
slice. The other is cut into 100 pieces
and you get 1 slice. Which one will you

get MORE pizza?

Let’s practice writing values as

fractions AND decimals!

Here’s an example:

5/10 = 0.5

They both are equal to five tenths

Write the following as decimals.

Fill in the Blank

Write the following as decimals.

3/10

.

Fill in the Blank

Write the following as decimals.

4/10

.

Fill in the Blank

Write the following as decimals.

7/10

.

Fill in the Blank

Write the following as decimals.

8/10

.

Answers

Notice, there is
1 zero in 10 so
you get 1 place

after the
decimal!

Write the following as decimals.

Fill in the Blank

Write the following as decimals.

5/100

.

Fill in the Blank

Write the following as decimals.

2/100

.

Fill in the Blank

Write the following as decimals.

9/100

.

Fill in the Blank

Write the following as decimals.

6/100

.

To write thirteen hundredths, you will write

two places after the decimal.

0.13

To write five hundredths, you will still write

two places after the decimal.

0.05

Write the following decimals as fractions!

Pay close attention to how many places

after the decimal you have!

0.15 =

0.07 =

0.5 =

0.1 =

Math Response

Write the following decimals as fractions! Pay close attention to how many places after the decimal you have! 

0.15

Type answer here

Correct Answer: \frac{15}{100}

Deg^°

Rad

Math Response

Write the following decimals as fractions! Pay close attention to how many places after the decimal you have! 

0.07

Type answer here

Correct Answer: \frac{7}{100}

Deg^°

Rad

Math Response

Write the following decimals as fractions! Pay close attention to how many places after the decimal you have! 

0.5

Type answer here

Correct Answer: \frac{5}{10}

Deg^°

Rad

Math Response

Write the following decimals as fractions! Pay close attention to how many places after the decimal you have! 

0.1

Type answer here

Correct Answer: \frac{1}{10}

Deg^°

Rad

Math Response

Write the following decimals as fractions! Pay close attention to how many places after the decimal you have! 

0.3 =

Type answer here

Correct Answer: \frac{3}{10}

Deg^°

Rad

Math Response

Write the following decimals as fractions! Pay close attention to how many places after the decimal you have! 

0.5 =

Type answer here

Correct Answer: \frac{5}{10}

Deg^°

Rad

Math Response

Write the following decimals as fractions! Pay close attention to how many places after the decimal you have! 

0.02 =

Type answer here

Correct Answer: \frac{2}{100}

Deg^°

Rad

Math Response

Write the following decimals as fractions! Pay close attention to how many places after the decimal you have! 

0.18 =

Type answer here

Correct Answer: \frac{18}{100}

Deg^°

Rad

Dropdown

Which has a greater value

0.3 or 3/100?


0.3 ​

Select answer

3/100

Can you see that

0.3 is MORE than 3/100?

Write as a mixed number

and decimal.

Whole

Part

She is not correct.
1 2/10 = 1.2. She
confused the place
values. The 2 in 1.02 is
in the hundredths
place!

Discuss with a
classmate: What is
another way you can
write 4.6? How do you
know they are
equivalent?

Closing Discussion:
How are fractions
and decimals
related?

One quarter is 0.25 or
2 dimes and 5 pennies

One nickel is 0.05 or

5 pennies

You try!

Word

Problem

Sara saves 12.04 each week
from babysitting. How many
dollars, dimes, and pennies
will she have saved after 5

weeks?

(answer next slide)

Sara saves $12.04 each week

12.04 x 5 = $60.20

She will save

60 dollars

2 dimes
0 pennies

12.04
12.04
12.04
12.04
+12.04
$60.20

Yes, this is also
worth 20 pennies
but we have a 0 in

the hundredths

place, so we’ll just
count the dimes in
the tenths place.

☺

Word

Problem

Kevin saves $9.21 each

week from doing his chores.

How many dollars, dimes,
and pennies will he have

saved after 4 weeks?

(answer next slide)

Kevin saves $9.21 each week

9.21 + 9.21 + 9.21 + 9.21 = $36.84

9.21 x 4 = $36.84

36 dollars

8 dimes
4 pennies

Word

Problem

Jacob has $25.00. He spends

$17.32 on a new baseball

jersey. How much money does
he have left? Don’t forget to

line up the place values!

(answer next slide)

$25.00
-$17.32

$7.68

4
9 10

1

14

He has $7.68 left.

LAST

Word

Problem

How many ways can you use
5 dollar bills, 1 dollar bills
dimes, quarters, nickels and

pennies to show

$13.24? Be ready to share!

(Students share out and teacher records their answers)

Closing Discussion: How are
decimals related to money?
Why don’t we have digits in
the thousands place when

writing money?