Converting common fractions to decimal fractions
Zamiana ułamków zwykłych na ułamki dziesiętne
Learning objectives
You will discover the methods of converting the common fractions to the decimal ones.
Learning effect
You convert common fraction into the finite decimal fractions.
You convert common fraction into the infinite decimal fractions.
You use English to describe the method of converting the common fractions into the decimal ones.
Bring the calculator for the lesson.
Revise the conversion of the decimal fractionsdecimal fractions into common ones, expansion and reduction of the common fractionscommon fractions and written division. Using the gained information about the conversion decimal fractionsdecimal fractions into the common ones write the common fractionscommon fractions in a form of decimal.
Fill the gaps with the one of the following numbers: 4,3; 2,3; 0,43; 0,27; 0,043 or 2,003 to get the correct equality.
a)
b)
c)
d)
e)
f)
Today you are going to convert the common fraction into the decimal ones.
Analyse the slideshow concerning the conversion of the common fractionscommon fractions into the decimal ones.

Zasób interaktywny dostępny pod adresem https://zpe.gov.pl/a/DsRn8VlJ8
Consider:
Which denominators of the common fractions should be found to convert them into decimal fractionsdecimal fractions?
What does the conversion of the common fraction into the denominators of 10, 100, 1000, … depend on?
Note, that:
Some common fractions can be converted into the fractions with denominators of 10, 100, 1000, …
The common fractions can be reduced to the denominators of 10, 100 or 1000, ..., if its denominatordenominator is a multiplemultiple of the number 10, 100 or 1000, … and its numeratornumerator can be reduced by the same number as the denominatordenominator.
The common fraction can be expanded to the denominatordenominator of 10, 100 or 1000, …, if its denominatordenominator is the divisordivisor of the number 10, 100, 1000, …
Using the gained information convert the common fractionscommon fractions into the decimal ones.
Write the common fractionscommon fractions in a form of the decimal fractionsdecimal fractions.
a)
b)
c)
d)
e)
f)
g)
h)
Consider:
Is it possible to reduce or expand every common fraction to get its denominatordenominator of 10, 100, 1000, …?
What operation does the fraction bar replace? What is the dividend of the common fraction? And what is the divisordivisor?
How can we get the quotation equal to the common fraction? How can it be calculated?
Note, that:
Not every common fraction can be reduced or expanded to get its denominatordenominator of 10, 100, 1000, …
The fraction bar replaces the division sign.
The numeratornumerator is a dividend and the denominatordenominator is a divisordivisor in the common fraction.
The quotation equal to common fraction can be gained by dividing its numeratornumerator by the denominatordenominator. The division can be done mentally, by using the written method or calculator.
Using the gained information and the calculator convert the common fractionscommon fractions into the decimal ones.
Write the common fractionscommon fractions in a form of the decimal ones. Use the calculator.
a)
b)
c)
d)
e)
f)
What have you noticed?
What fractions have the finite number of digits after the decimal point, so finite decimal expansionfinite decimal expansion? And what fractions have the infinite decimal expansioninfinite decimal expansion?
An extra task:
Find out on the Internet the information about the recurring decimal fractionsdecimal fractions. Give the examples of the common fractionscommon fractions which after conversion to the decimal ones have periodic expansion.
Remember:
Some common fractionscommon fractions can be converted into the fractions with denominators of 10, 100, 1000, … by their expanding or reducing.
The common fraction can be always converted into the decimal fraction by dividing its numeratornumerator by the denominatordenominator. The decimal expansion can be either finite or infinite.
Do the summarizing tasks.
Exercises
Determine which sentences are true.
- The fraction equals the fraction 5,8.
- The fraction is the infinite repeating decimal.
- The fraction is less than 0,2.
- The numbers and 5,12 are equal.
Convert the common fractions to the decimal ones. Next, put them in the ascending order.
Convert the common fractions to the decimal ones.
a)
b)
c)
d)
Describe the method of converting the common fractions into the decimal ones in English.
Indicate which pairs of expressions or words are translated correctly.
- ułamki zwykłe - common fractions
- rozszerzanie ułamka zwykłego - expanding the common fraction
- skracanie ułamka zwykłego - reducing the common fraction
- rozwinięcie dziesiętne skończone - finite decimal expansion
- licznik - denominator
- mianownik - numerator
- infinite decimal expansion
- skracanie ułamka zwykłego
- reducing the common fraction
- expanding the common fraction
- ułamki zwykłe
- rozwinięcie dziesiętne skończone
- rozszerzanie ułamka zwykłego
- common fractions
- rozwinięcie dziesiętne nieskończone
- finite decimal expansion
Glossary
ułamki zwykłe
Nagranie dostępne na portalu epodreczniki.pl
wymowa w języku angielskim: common fractions
ułamki dziesiętne
Nagranie dostępne na portalu epodreczniki.pl
wymowa w języku angielskim: decimal fraction
mianownik
Nagranie dostępne na portalu epodreczniki.pl
wymowa w języku angielskim: denominator
dzielnik
Nagranie dostępne na portalu epodreczniki.pl
wymowa w języku angielskim: divisor
rozszerzanie ułamka zwykłego
Nagranie dostępne na portalu epodreczniki.pl
wymowa w języku angielskim: expanding the common fraction
rozwinięcie dziesiętne skończone
Nagranie dostępne na portalu epodreczniki.pl
wymowa w języku angielskim: finite decimal expansion
rozwinięcie dziesiętne nieskończone
Nagranie dostępne na portalu epodreczniki.pl
wymowa w języku angielskim: infinite decimal expansion
wielokrotność
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wymowa w języku angielskim: multiple
licznik
Nagranie dostępne na portalu epodreczniki.pl
wymowa w języku angielskim: numerator
skracanie ułamka zwykłego
Nagranie dostępne na portalu epodreczniki.pl
wymowa w języku angielskim: reducing the common fraction
Keywords
common fractionscommon fractions
expanding the common fractionexpanding the common fraction – mnożenie licznika i mianownika ułamka przez tę samą liczbę naturalną większą od 1
finite decimal expansionfinite decimal expansion
infinite decimal expansioninfinite decimal expansion
reducing the common fractionreducing the common fraction - dzielenie licznika i mianownika ułamka przez tę samą liczbę naturalną większą od 1