MODULE V
Student Book
ADDITIVE FRACTIONS
For Class 1 SMP / MTs
By :Marsigit

Reviewed By : Eka Sulistyawati

A.    Basic Competencies and Standars Competence

Standards of competence      :
Understanding and perform arithmetic operations number in problem solving

Basic Competence:

Know fractions and perform operations of fractions numbers

B.     Learning Outcome Indicators

Complete the addition operation involving fractions

C.     Addition Fractions

Issue 1: Amir bought a cake which was cut into 4 equal parts. Amir eating ¼ cake then that ½ is given to his brother. How many parts of cake Amir has eaten and given to his brother?

To solve the problem above is easy,isn,t it?

a.       Draw an arbitrary rectangle.

b.      Then divide the rectangle into four equal parts.

c.       Looks, many cakes are eaten Amir is ¼ = 1 part shaded, and which given to his brother 1/2 = 2 part shaded. So the cake is eaten by Amir and the cake given to his brother is 3 parts shaded area or 3/4 parts of cake.So ¼ + ½ = ¾

Issue 2: Consider the following context and answer the question? The Gasoline Mr Tono’s car is only 1/3 tank. Then Mr. Tono buy gasolin ½ tank. How many existing gasoline in tank Mr Tono’s car? Discuss and answer. The number of existing gasoline in tank Mr Tono’s car now is 1/3  + .......

The next step is to equate the denominator of both fractions, so obtained
1/3 + ..... =2/6 +......=.......

So the number of gasolin in the tank Mr Tono’s car now is ........... section tank.

Issues 3: Determine the sum of 11/12 + 12/13 Take these steps: Least Common Multiple (KPK) of 12 and 13 is 12 x 13 = .......... The sum fraction form: 11/12 + 12/13 =11x13/156 + 12x12/156 = 143/156 + 144/156 =........

So, 12/11 + 13/12 = .............

Issue 4: How much does it result if 4 ¼ + 1 ½ + 4 1/10 + 3 1/8 and how to
look for it? To solve this problem do the following activities:

Task Group:  

a.       Take a measure instrument or a ruler, then take a few things that have varying length.

b.      Measure each object with cm unit and the desimal numbe of one digits behind the commas.

c.       Record the results of these measuring

d.      Then do the sum of data that obtained

Issues 5: Determine the sum of 8 ¾ + 7 2/5

Perform these steps:

Least common multiple of 4 and 5 are ......Shape the mixture fraction into
8 ¾ + 7 2/5      = (8 + 7)          + ( 15/20 + .....)

= 15                 + .....

=......

So 8 ¾ + 7 2/5 =.....

D.    Your conclusions?

Do you agree with the following conclusions? Explain it. The number of fractions with same denominator, is the number of numerator divided by the denominator sum of the mixture fraction can be done by adding the chopped number with natural numbers and fraction number with farction numbers.