LESSON 3 - FRACTIONS

Lead-in

name parts of a whole

indicate division

compare two quantities


Always remember: denominator can never be 0 !

TYPES OF FRACTIONS:

4/7 common fraction ( vulgar fraction)

Proper Fractions Numerator < Denominator (e.g 3/4)

Proper fractions have the nominator part smaller than the denominator part

 

Improper Fractions Numerator > Denominator or Numerator = Denominator

(e.g 9/4 )

Improper fractions have the nominator part greater or equal to the denominator part

Mixed Fractions

Mixed fractions have a whole number plus a fraction

 

0.342  -  decimal fraction

Finite decimal (terminating decimal) e.g. 5,625

Infinite decimal e.g. 1, 35721…

 

Recurring ( repeating) decimal ( periodic decimal ) e.g. 0,3333…. = 0,(3)

 

5,76589 ≈ 5,766 Aproximation to three decimal places !

 

EQUIVALENT FRACTIONS:

Simpliflying ( reducing ) fraction to lower terms - cancellation of fractions

 

 

fraction in its lowest terms

READ ME

 

1/2

a/one half

połowa

1/3

a/one third

jedna trzecia

1/4

a/one quarter

jedna czwarta
(dosł. jedna ćwierć)

1/5

a/one fifth

jedna piąta

1/6

a/one sixth

jedna szósta

2/3

two thirds

dwie trzecie

3/4

three quarters

trzy czwarte (trzy ćwierci)

4/5

four fifths

cztery piąte

1 1/4

one and a quarter

jeden i jedna czwarta

1 1/2

one and a half

jeden i pół

 

 

 

1.5

one point five

2.25

two point two five

3.75

three point seven five

1.05

one point oh/nought five

0.72

point seven two

 

 

Licznik czytamy jak zwykły liczebnik - one, two, four

Mianownik 'porządkujemy' liczebnikiem porządkowym - sixth, fifth, third, etc. (oprócz ułamków 1/2 i 1/4, które czyta się tak, jak podano powyżej).

Jeśli licznik jest większy niż 'jeden', to nasz mianownik oprócz tego otrzymuje liczbę mnogą - sixths, fifths, thirds, quarters.

USEFUL PHRASES

round the number to the nearest thousandths- zaokrąglić liczbę do części tysięcznych

decimalisation - przekształcenie na ułamek dziesiętny

lcd - lowest common denominator - najmniejszy wspólny mianownik

reciprocal - odwrotność

 

LABEL TRUE OR FALSE

The decimal point separates the whole-number part and the fractional part of a decimal fraction. (T/F)

 

A mixed number is a sum of a whole number and a proper fraction.(T/F)

 

Equivalent fractions are simply different names for the same number. (T/F)

 

When mixed numbers are involved in multiplication it is easiest to change them into improper fraction and then apply the multiplication rule for fractions. (T/F)

 

In multiplying two or more fractions we can divide any factor of the numerator and any factor of the denominator by the same nonzero number to simplify the product. ( T/F)

 

 

SELECT THE PHRASE

that best completes the sentence : must be, cannot be, can be but needn’t be.

 

In a common fraction the denominator …………..........equal to 0.

 

To add two like fraction the numerators ......................  added while the numerator ........................ changed.

 

In subtracting two like fraction the subtraction of numerators and denominators ............... done.

FALSE FRIENDS

vulgar fraction – ułamek zwykły

vulgar - trywialny, pospolity, prostacki

decimal fraction : in English 3.25 in Polish 3,25

Przecinkiem oddziela się w języku angielskim setki od tysięcy, tysiące od milionów itd. : 125,430,560

TIME FOR PROBLEMS

1) Round to the nearest thousandth :

2.3597 …................

250,1342................

 

2) Convert 7 5/8 to an improper fraction ….............................

 

3) Reduce fraction to its lowest terms :

48/84 = ..............................

 

4) Write equivalent fractions with the least common denominator for 3/8, 5/12 and 7/15

 

5) Estimate the sum. Round each number to the nearest whole number, then add.

7 6/19 + 2 4/7 = …....The sum is approximately............................

 

6) A sheet of paper is 6 1/2 cm long by 4 3/4 cm wide. What is its area ?

 

 

Make test !

Materials

Fractions.pdf
Adobe Acrobat Document 117.4 KB
exercisefraction1.pdf
Adobe Acrobat Document 99.8 KB
exercisefraction2.pdf
Adobe Acrobat Document 87.8 KB