So I'll start my story with even numbers. What are even numbers? Any integer that can be divided by two without a remainder is considered even. In addition, even numbers end with one of the given number: 0, 2, 4, 6 or 8.
For example: -24, 0, 6, 38 are all even numbers.
m=2k is the general formula for writing even numbers, where k is an integer. This formula may be needed to solve many problems or equations in elementary grades.
There is another kind of number in the vast realm of mathematics - odd numbers. Any number that cannot be divided by two without a remainder, and when divided by two, the remainder is equal to one, is called odd. Any of them ends with one of these numbers: 1, 3, 5, 7 or 9.
Example of odd numbers: 3, 1, 7 and 35.
n=2k + 1 - a formula that can be used to write any odd numbers, where k is an integer.
Addition and subtraction of even and odd numbers
There is a pattern in adding (or subtracting) even and odd numbers. We have presented it withthe table below to make it easier for you to understand and remember the material.
Operation |
Result |
Example |
| Even + Even | Even | 2 + 4=6 |
| Even + Odd | Odd | 4 + 3=7 |
| Odd + Odd | Even | 3 + 5=8 |
Even and odd numbers will behave the same if you subtract rather than add them.
Multiplication of even and odd numbers
When multiplying even and odd numbers behave naturally. You will know in advance whether the result will be even or odd. The table below shows all possible options for better assimilation of information.
Operation |
Result |
Example |
| EvenEven | Even | 24=8 |
| EvenOdd | Even | 43=12 |
| OddOdd | Odd | 35=15 |
Now consider fractional numbers.
Decimal representation of a number
Decimal fractions are numbers with a denominator of 10, 100, 1000 and so on, which are written without a denominator. Kissesthe part is separated from the fractional part using a comma.
For example: 3, 14; 5, 1; 6, 789 are all decimals.
Various mathematical operations can be performed with decimals, such as comparison, summation, subtraction, multiplication and division.
If you want to equalize two fractions, first equalize the number of decimal places by assigning zeros to one of them, and then, discarding the comma, compare them as whole numbers. Let's look at this with an example. Let's compare 5, 15 and 5, 1. First, let's equalize the fractions: 5, 15 and 5, 10. Now we write them as integers: 515 and 510, therefore, the first number is greater than the second, which means 5, 15 is greater than 5, 1.
If you want to add two fractions, follow this simple rule: start at the end of the fraction and add first (for example) hundredths, then tenths, then integers. This rule makes it easy to subtract and multiply decimals.
But you need to divide fractions as whole numbers, at the end counting where you need to put a comma. That is, first divide the integer part, and then the fractional part.
Decimal fractions should also be rounded. To do this, select to what decimal place you want to round the fraction, and replace the corresponding number of digits with zeros. Keep in mind that if the digit following this digit was in the range from 5 to 9 inclusive, then the last digit that remains is increased by one. If the digit following this digit was in the range from 1 to 4 inclusive, then the last remaining one is not changed.
