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In this video we will take a look at the four different operations.
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We will take a look at what they are called and important rules and concepts that we need to know before using the operations.
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The four mathematical operations are: addition, subtraction, multiplication and division.
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The symbol used for the different operations is called an operator.
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If we start by looking at the operation addition, we use a plus sign or the operator plus +.
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For subtraction, we use the minus sign, or the operator minus -, to show
that one number should be subtracted from another.
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When it comes to multiplication, there actually are a few different symbols that can be used to show that this particular operation is performed.
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A cross/an x, a star or a vertically centered dot are the the different symbols possible when performing the operation multiplication.
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When, for example, a computer is performing a multiplication, the symbol used is most often a star. On the other hand, the schoolbooks usually use the centered dot.
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Also the operation division, can be written with a few different symbols or
operators.
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A dash with a dot over and under, slash or a
horizontal bar can be used to show that one numbers shall be divided by another.
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When performing an operation of any kind, the numbers in the operation have different purposes and thereby also different names. We will take a look at these names.
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So, when numbers are being added, subtracted, multiplied or divided by each other, the numbers have different names.
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These names are important to know since these are often used
when explaining calculations.
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We start with the operation adding. Here we say that we add two or more numbers together. The symbol plus (+) is used.
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The numbers added together are called terms and
result is called the sum.
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So if the terms 3 and 5 are added, we then get the sum 8.
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In the the operation subtraction, we say that we subtract two numbers or more. The symbol
minus (-) is used.
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Here, the numbers that are being subtracted, are also called terms, but the result is instead called a difference.
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So if the term 5 is subtracted by the term 3 we will then get 2 as our difference.
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We also want to mention that one can easily confuse the operation
subtraction with the designation of a negative number, where the minus sign (-) is also used.
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Therefore it is good to write the negative number in parentheses
so that one can see the difference between them.
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The next operation that we will look at is called multiplication,
and here we say that we multiply the numbers together.
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Here, the numbers that are being multiplied are called factors, and the result is called a product.
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So if we multiply the factors 5 and 3, we get the product 15.
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Finally, we take a look at the operation division and here we say that numbers are being divided, or that we divide numbers.
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We call the number that is being divided the numerator, and number that the numerator is being divided by, is called the denominator.
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The result of the division is called a quota or quotient.
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So if we divide the numerator 15 by the denominator 3, we get the quotient 5.