Fractions Decimals and Percents Ms King Math 7

Fractions, Decimals, and Percents Ms. King Math 7 Review

A Quick Review n Fractions, decimals, and percents are all parts of a whole. They are also related and can be converted back and forth. 1 0 0 . 25 . 50 . 75 0% 25% 50% 75% 1 100%

Decimals n Decimals are like fractions because they also represent parts of a whole, however, decimals use the base ten system by place value. The place is named by the furthest right number. tenths, hundredths, thousandths, ten thousandths, hundred thousandths……. 0. 1 is said “one tenth” because the furthest right number is in the tenth place. 0. 17 is said “seventeen hundredths” for the same reason, How would we say 0. 83 “Eighty-three hundredths” How would we say 0. 015? “fifteen thousandths, ”

Converting decimals to fractions n Converting decimals to fractions is easy because all we have to do is read the decimal and it sounds the same as when we read the fraction. We read 0. 3 as “three tenths. ” which is n 0. 41 is read “forty-one hundredths. ” n

n . 07 n . 13 n . 107

Fractions in base 10 n Fractions in base 10 (denominator 10, 1000……. . ) are easy because they are also read the same way as decimals

Say it and Write it

Converting Fractions to Decimals n n n If the fraction has a denominator in base ten (10, 100, 1, 000 etc. ) It works the same way. is 0. 07 both are read “seven hundredths. ” If the fraction does not have a base ten denominator, you must use long division until you get a repeating or terminating decimal.

Dividing out a Fraction When dividing the fraction, it is important to make sure you have the right number “in the house, ” or inside the division symbol house basement house

Dividing out a Fraction When dividing the fraction, it is important to make sure you have the right number “in the house. ” or inside the division symbol house basement house

Let’s Try a Few n Convert 0. 49 to a fraction n Convert. 083 to a fraction n Convert to a decimal

Let’s Try a Few n Convert 0. 49 to a fraction n Convert. 083 to a fraction n Convert to a decimal

These are called terminating decimals n A terminating decimal ends

A Repeating Decimal n Ummmmmm it repeats. Use a bar to show it repeats

Quick Check!!!! n 1) convert 0. 16 to a fraction n 2) convert to a decimal n 3) convert to a decimal

Converting Numbers into Percents n When you have a fraction with a denominator in n base 10 (10, 100, 1, 000), numbers can be easily converted into percents. The word percent literally means per hundred. means you have 40 per hundred or 40% n How could we easily find what percent n is?

Converting Decimals to Percents n n n Lucky for us, decimals are ALL in base ten. 0. 72 means 72 per hundred or 72%. What happens if we have 0. 851 How many hundredths are there? 85 The left over is just a decimal 85. 1% An easy rule for converting decimals to percents is to simply move the decimal 2 places right.

Let’s Try Some

Percents to Decimals and Fractions n To convert a percent to a decimal, we do the reverse. Instead of moving the decimal 2 places right, we move it 2 places left and drop the % sign.

Try One on Your Own Convert 27% into a decimal Now convert 0. 27 into a fraction

Closure n How do you convert a decimal to a fraction? Write it as it is read n How do you convert a fraction to a decimal? Long divide n How do you convert a decimal to a percent? Move the decimal right 2 places n How do you convert a percent to a decimal? Move the decimal left 2 places