How to subtract fractions?
Every child goes to school and everyonea small schoolboy, in the end, there comes a time when the topic of subtraction and addition of fractions is given for studying. And even parents often can not help the child understand this problem, because we increasingly use calculators and other computer equipment, and we consider, as a rule, not fractions, but money. Therefore, this article should be read to both schoolchildren and their parents.
How to properly subtract fractions?
So, let's begin our analysis of the topic - how to subtract fractions. First of all, in order to successfully cope with this task, it is necessary to understand how to bring to the common denominator two available fractions. To do this, we need to find the smallest number that both fractions will share simultaneously, and then multiply the numerator and denominator of the fractions by this number. But this is a rather complicated method. The simplest way is to multiply the fractions by the denominators of each other. Example: 3/7 - 2/6 =?
To reduce these fractions to a common denominatormultiply the denominator and numerator of the first fraction by the number in the denominator of the second fraction. The same operation is performed with the second fraction, only multiplying by the denominator of the first fraction. Thus, we obtain: 3 * 6/7 * 6 - 2 * 7/6 * 7 = 18/42 - 14/42 Next, simply subtract the numerators of the fractions, leaving the denominator the same, and reduce the resulting fraction: 18/42 - 14/42 = 4/42 = 2/21
Now let's try to figure out how to subtractmixed fractions. When subtracting mixed fractions, a similar principle should be used, but the fraction should be reduced to the form a / b. To do this, you need to multiply the denominator by an integer, and then add the numerator to the resulting number. Example: 1 (2 * 1 + 1) / 2 = 3/2
Now, let's figure out how to subtractdecimal fractions. Here things are a bit simpler. To subtract decimal fractions, you need to cast the fractions to such a kind that they have the same number of symbols after the comma. To do this, you need a fraction that has a smaller number of symbols after the comma, put as many zeros as possible to equalize the number of characters. Then it is necessary to subtract the fraction into a column as an ordinary number.
So, we figured out how to subtract a fraction from a fraction. Now let's figure out how to subtract a fraction from the number. It's still simpler here. Any number can be reduced to the form of a fraction, with any denominator. It is enough only to understand that a unit is a fraction with the same numerator and denominator. Otherwise, subtraction occurs according to the above principle.
Summing up this article, I want to note that this information is necessary not only for schoolchildren, but also for parents who want to help their students understand this issue.