2.2.1 Converting Fractions to Decimals

Let’s relate fractions to decimals. If we have a whole pie and one divided by two a pie, we have 1 and one divided by two of a pie. Not only is that hard to read and type; it’s also hard to say! So, to represent whole numbers and fractions of whole numbers, we use decimals as we have just seen in the last section. We do this by using a decimal point to separate the whole number from the fraction.

For example, say you needed to write out 2 and three divided by 10 (three tenths) as a decimal. The whole part is 2 and the fractional part is three divided by 10. Thus, we would write the 2 to the left of the decimal point and the fractional part to the right of the decimal point. Thus, it would be written as 2.3.

Pencast symbolLet’s reinforce this concept with more explanation (Click on “View document”).

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Now try a few conversions on your own. Check out the next activity.

Activity symbol Activity: Fractions to Decimals

Rewrite each of the following fractions as a decimal.

(a) two divided by 10.

Hint symbol

Discussion

If the number does not have a whole number part, a zero is written in the units. This makes the number easier to read (it’s easy to overlook the decimal point). The first placeholder to the right of the decimal is the tenths. How many tenths do you have for each given number?

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Answer

(a)two divided by 10 equals 0.2 (because there are zero whole parts).

(b) three divided by 10.

Solution symbol

Answer

(b) three divided by 10 equals 0.3 (because there are zero whole parts).

(c) 1 and two divided by 10.

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Answer

(c) 1 and two divided by 10 = 1.2.

(d) 3 and 3/100.

Solution symbol

Answer

(d) 3 and 3/100 = 3.03.

2.2 Using a Number Line

2.2.2 Different Ways to Write Numbers