How many small boxes make up the whole grid? (100)
Have a volunteer come to the projector, count out a row or column (10 squares),
and shade it.
What does the shaded part represent? (one tenth of a whole)
Explain, or ask students to explain, ways to read and write this decimal
(one-tenth, 0.1, or 1/10). The first place to the right of the decimal point
is the tenths place.
Have a second student come to the projector and shade in only one square
on the grid. Ask:
What does the shaded part represent? (one hundredth)
What are ways to read and write this decimal? (one hundredth, 0.01,
The second place to the right of the decimal point is the hundredths
Is 0.1 greater or less than 0.01? (greater)
How much greater? (10 times)
Explain that one tenth (0.1) and ten hundredths (0.10) have the same value.
Clean the overhead, and have a third student shade both values to illustrate
that they are the same.
If the first place to the right of the decimal is called the tenths
place, and the second place to the right of the decimal is called the hundredths
place, what do you think the third place to the right of the decimal point
is called? (the thousandths place)
What are ways to read and write one thousandth? (one thousandth,
0.001, or 1/1,000)
Ask students to name instances when it is important to calculate and record
numbers less than 1 (Possible answers: time, money, scientific measurements).
Use instances from life to show the class how each of the following decimals
is written and read.
Marcel’s slice of pizza cost $1.35.
In the 1988 Summer Olympics, Carl Lewis won the gold medal for running the
100-Meter Dash in 9.92 seconds.
An inch is equal to 2.54 centimeters.
The average body temperature is 98.6° Fahrenheit.
When comparing decimals, begin on the left and compare the digits in each
Compare 0.11 and 0.12.
In the tenths place the digits are the same. Look at the hundredths. 2 is
greater than 1, so 0.12 > 0.11.
Compare 0.02 and 0.120.
The ones are the same. 1 is greater than 0 in the tenths place, so 0.120
Compare 2.17 and 0.99.
The ones are different. Since 2 is greater than 0, 2.17 > 0.99.
Remind students that when there are non-zero digits on both sides of the
decimal point, they should say, "and," where they see the decimal
point. For example, 2.17 is read, "two and seventeen hundredths."
Use models on a 10 x 10 grid as necessary to guide the class in comparing
decimals numbers using > and <.