Fractions, decimals and percentages: Multiplying and dividing fractions. 

3rd year of secondary education.  
Operations with fractions  
How much money would an heir inherit if he was to inherit 4/7 (four sevenths) of a total inheritance of € 8,400,000 (eight million four hundred thousand) euros? We are going to use the following window to solve the problem. Read the instructions carefully.  
 
Write
down the operation you had to carry out on the total QUANTITY to find out 4/7 of
it.
Carry out the same operation with other quantities and fractions. For example, find out 1/5 of 100, or 3/4 of 200 etc.  
When a fraction acts as an operator on a quantity C, we get the answer by multiplying a*C and dividing the result by b. of C = * C = 
Multiplying and dividing fractions  
We can use the following formulae to multiply and divide fractions:
TO
MULTIPLY FRACTIONS: TO
DIVIDE FRACTIONS:  
 
Exercise 7. Multiply and divide the following fractions and cancel the answers down to the lowest terms. Then, check your results in this window:
a) 4/3 * 1/6
c) 2/5 * 3/8
e) 20/9*15/4 
Exercise 8: The magic square.  
This is a magic square. The reason being that the sum of all the lines
(horizontal, vertical or diagonal) is always the same. We call the sum of any
line of the square the magic number.
Work out the answers in each little square and calculate the magic number. Then, fill in the empty little squares with the missing number. Read the instructions underneath to check your answers.
 

Ángela Núñez Castaín  
Spanish Ministry of Education. Year 2001  
Except where otherwise noted, this work is licensed under a Creative Common License