The mathematics is quite difficult, but very interesting science ""tied"" on figures. Their combinations there can be a huge number, but all these numbers can be divided into only two categories: even and odd.

## It is required to you

- Box of matches.

## Instruction

1. To define what numbers are even, and what odd, rather simply. For this purpose you will need to halve a single number. That which will share on two without the rest will be even. If after division there is an indivisible figure, the number will be called odd. The figure zero which does not bear in itself numerical value by default is considered even number.

2. According to definition in theories of numbers, parity is a characteristic of an integer. She speaks about its ability to be multiple to two, at the same time remaining indivisible on the 100-th shares. If you explain these elementary concepts to the child, supply the story with a bright example. Take a certain quantity of matches (you will need no more than ten). Collect them in one small group or empty boxes then begin to play with the child an informative game.

3. Let each of you two will serially extend from a box on one match. If as a result at each player the equal quantity of matches turns out, so their number in a box was even (it shared on two). If at someone from you it was one match less, than at another, it turns out that the initial quantity of matches was odd (time remained the indivisible rest).

4. If you consider even and odd numbers in a decimal form, then the last figure of number will be considered as defining. If it is divided into two without the rest, the number is even if does not share, then, respectively, will be odd.

5. If you need to learn what number (couples or an odd number) will turn out as a result of various mathematical operations, do not trouble yourself excess calculations (determination of the final sum of numbers and its halving). Remember that at addition, subtraction and multiplication of even numbers, according to rules of arithmetics, only even numbers are always formed. At division of odd number into the even turned-out number cannot be whole. At multiplication of odd number on even and vice versa as a result will always be ""couples"".