Numbers with Two Decimal Digits - Hundredths

This is a complete lesson with instruction and exercises about numbers with two decimal digits (hundredths), meant for fourth grade. On a number line, we get hundredths by simply dividing each interval of one-tenth into 10 new parts. Or, we can look at fractions. The video below also includes an explanation of why you can "tag" or "add" zeros to the end of a decimal and its value does not change.

You have seen this number line in the previous lesson. In it, the distance from 0.0 to 0.1 is one tenth. Now, we will DRAW nine tiny lines between 0.0 and 0.1, dividing that distance into TEN new parts. Now, repeat this process between 0.2 and 0.3, dividing that distance into TEN new parts. If you repeated this process between 0.3 and 0.4, and then between 0.4 and 0.5, etc., into how many parts would you divide the number line from 0 to 1? ________ parts These new parts are therefore hundredth parts, or hundredths.

The number line below zooms in to the previous number line, from 0 to a little past 0.3.  The interval from 0 to 0.1 has been divided into ten parts, and similarly the interval from 0.1 to 0.2, etc. Each interval is one hundredth. Now look at the numbers below the tick marks. They have two digits after the decimal point − or we say they have two decimal digits. The number 0.28 is read as twenty-eight hundredths and is the same as  28 100 . The number 0.06 is read as six hundredths and is the same as  6 100 . The number 2.34 is read as two and thirty-four hundredths and is the same as 2 34 100 .

We can also illustrate hundredths by dividing a square into a hundred parts.       This represents 32 hundredths. 32 100  = 0.32       This is twenty hundredths.    20 100  = 0.20 It is also two tenths: 2 10  = 0.2, because each of the 10 columns is one-tenth of the whole.

1. Color parts to show the equalities. Write the decimal in (b) and (c).

a.  0.50 = 0.5

b.  0.10 = _____

c.  0.80 = ______

2. What numbers do the pictures illustrate? Write them as a fraction and as a decimal.

a.	b.
c.	d.

3. Color to illustrate the decimals. Then write them as fractions.

a.   0.52 =

b.  0.7 =

c. 0.09 =

d. 1.08 =

4. Write the fractions as decimals.

5. Write as fractions.

6. Mark these decimals on the number line below:  

    1.55    1.11   1.28   1.39  1.88   1.02   1.67   1.99   1.74   1.43  1.90  1.06  1.20

7. Fill in the missing hundredth parts under the tick marks on the number lines.

8. Make a number line with the hundredths tick marks from 0.6 till 0.7.

9. We also use decimal numbers to write money amounts. A cent is a hundredth part of a dollar.
    So $5.12 means 5 whole dollars and 12 hundredths of a dollar, or 12 cents.

    With dollar-cent amounts, we always use two decimal digits after the point.
    So, what is the usual way of writing $0.6 ?

 
10. Compare. Write <, >, or = between the numbers.

a.  0.51		0.49	b.  4.5		4.50	c.  0.1		0.01	d.  0.50		1 2
e.  1.12		1.35	f.  5.35		3.58	g.  4.06		4.6	h.  2.7		2.07
i.  2.67		2 1 2	j.  1.01		1.1	k.  1.7		1 1 2	l.  4.12		4.2