Pupils of schools get an idea of fractions at the initial stage of training. Do not forget about fractions and in high school, but it is allowed to find them on the calculator, and therefore the principle of emergence of fraction is forgotten. In practice it is simpler to solve problems by means of the main property of fractions, than at random to gather buttons on the calculator
It is required to you
- - Textbook by mathematics for the 5th class.
Instruction
1. So, let's deal, with definition of a part from whole. For this purpose make the drawing of a square or rectangle, it is the best of all on a leaf in a section. Divide a square on sections, it will be the shares equal to a part of a single whole. Fractions are different, for example, ordinary – 1/2, 3/7, 1/4, mixed – 1 ½, 2 ½5 ¼, decimal fractions – 0.25, 0.5, 0.7.
2. All fractions depend on the main property of fractions – the reduced fractions, solve problems without calculator.
3. Fractions can be transferred from one look in another. For example, the fraction 25/100 can be written down as 0.25. The fraction can be reduced, it will turn out ¼. Happens that the decimal fraction does not need to be reduced. For example, 0.3 and will remain 3/10 – this fraction is not reduced. But consider, not all common fractions can be presented in the form of decimal. Not to find decimal fraction from 1/3, 6/7, 1/7, and there is a lot of such not transferred fractions.
4. Try to find decimal fraction from 3/20. For a start spread out a denominator of this fraction to simple multipliers, for example 5*2*2. Write down an example so: 3/20 = 3/20*5/5=15/100=0.15. So that to find decimal fraction, factorize a denominator of a common fraction, balance quantity of the five and two, choose the only multiplier. Set knowledge - find decimal fraction from 3/50. Factorize a denominator 50=2*5*5, so the two needs to be presented in the form of fraction 2/2. 3/50*2/2=6/100=0.06.
5. To find decimal fraction from a common fraction divide its numerator into a denominator. For example, take 5/8, divide 5 into 8, receive 0.625. The decimal decimal can be recurring. For example, 18/7 it is impossible to turn into exact decimal fraction because if 18 to divide into seven the infinite number will turn out.