You will need
- Basic knowledge in mathematics.
Suppose you have two fractions: 2/3 and 7/8. First find the least common dividend of the denominators of these fractions, and then both fractions to him. In our case, the least common divisible is the number 24, that's up to him and we allow the fraction.
To bring the first fraction to the lowest common delimma found, multiply the numerator of the first fraction to the quotient of this divisor by the numerator. In our case it will be: 24/3=8. That is the numerator of the first fraction must be multiplied by 8. Similarly we find the multiplier for the second fraction: 24/8=3. That is the numerator of the second fraction must be multiplied by 3.
Multiply the numerators of the fractions on received private. In the result, the fractions get a common denominator: 16/24 and 21/24.
To check whether you are brought to a common denominator, just reduce each of the fractions, if you got the original shot - and rightly so.
Order to find the least common multiple of the denominators can be the numerator of the first fraction times the denominator of the second, and the second numerator multiplied by the denominator first. And the overall numerator will be equal to the product of the denominators. This method is suitable if the number of fractions is small and they just multiply in my mind.