The Basic Operations In basic mathematics there are many ways of saying the same thing:
Symbol and Words Used: + Addition,( Add, Sum, Plus, Increase, Total)
- Subtraction, (Subtract, Minus, Less, Difference, Decrease, Take Away, Deduct)
× Multiplication,( Multiply, Product, By, Times, Lots Of)
÷ Division, (Divide, Quotient, Goes Into, How Many Times)
Symbol and Words Used: + Addition,( Add, Sum, Plus, Increase, Total)
- Subtraction, (Subtract, Minus, Less, Difference, Decrease, Take Away, Deduct)
× Multiplication,( Multiply, Product, By, Times, Lots Of)
÷ Division, (Divide, Quotient, Goes Into, How Many Times)
.. bringing two or more numbers (or things) together to make a new total.
The numbers to be added together are called the "Addends":
The numbers to be added together are called the "Addends":
... taking one number away from another.
Minuend - Subtrahend = Difference
Minuend: The number that is to be subtracted from.
Subtrahend: The number that is to be subtracted.
Difference: The result of subtracting one number from another.
Minuend - Subtrahend = Difference
Minuend: The number that is to be subtracted from.
Subtrahend: The number that is to be subtracted.
Difference: The result of subtracting one number from another.
.. (in its simplest form) repeated addition.
Here we see that 6+6+6 (three 6s) make 18
It could also be said that 3+3+3+3+3+3 (six 3s) make 18
But you can also multiply by fractions or decimals, which goes beyond the simple idea of repeated addition:
Example: 3.5 × 5 = 17.5
which is 3.5 lots of 5, or 5 lots of 3.5
Here we see that 6+6+6 (three 6s) make 18
It could also be said that 3+3+3+3+3+3 (six 3s) make 18
But you can also multiply by fractions or decimals, which goes beyond the simple idea of repeated addition:
Example: 3.5 × 5 = 17.5
which is 3.5 lots of 5, or 5 lots of 3.5
Division is ...
... splitting into equal parts or groups. It is the result of "fair sharing".
Division has its own special words to remember.
Let's take the simple problem of dividing 22 by 5. The answer is 4, with 2 left over. Here we illustrate the important words:
... splitting into equal parts or groups. It is the result of "fair sharing".
Division has its own special words to remember.
Let's take the simple problem of dividing 22 by 5. The answer is 4, with 2 left over. Here we illustrate the important words:
A Fraction is ... .. part of a whole.
A number written with the bottom part (the denominator) telling you how many parts the whole is divided into,
and the top part (the numerator) telling how many you have.
A number written with the bottom part (the denominator) telling you how many parts the whole is divided into,
and the top part (the numerator) telling how many you have.
A Decimal is ... ... a number based on 10. The numbers we use in everyday life are decimal numbers, because there are 10 digits (0,1,2,3,4,5,6,7,8 and 9).
it is also used to mean a number that uses a decimal point followed by digits as a way of showing values less than one.
Example: 1.9 is a decimal number (one and nine tenths)
it is also used to mean a number that uses a decimal point followed by digits as a way of showing values less than one.
Example: 1.9 is a decimal number (one and nine tenths)
A Percentage is ... ... parts per 100. The symbol is %
Example: 25% means 25 per 100 (25% of this box is green)
Example: 25% means 25 per 100 (25% of this box is green)
Average
You calculate the average by adding up all the values, then divide by how many values.
Example: What is the average of 9, 2, 12 and 5? Add up all the values: 9 + 2 + 12 + 5 = 28
Divide by how many values (there are four of them): 28 ÷ 4 = 7
So the average is 7
You calculate the average by adding up all the values, then divide by how many values.
Example: What is the average of 9, 2, 12 and 5? Add up all the values: 9 + 2 + 12 + 5 = 28
Divide by how many values (there are four of them): 28 ÷ 4 = 7
So the average is 7
How to Find the Mean
The mean is just the average of the numbers.
It is easy to calculate: add up all the numbers, then divide by how many numbers there are.
In other words it is the sum divided by the count.
Example 1: What is the Mean of these numbers? 6, 11, 7
The mean is just the average of the numbers.
It is easy to calculate: add up all the numbers, then divide by how many numbers there are.
In other words it is the sum divided by the count.
Example 1: What is the Mean of these numbers? 6, 11, 7
- Add the numbers: 6 + 11 + 7 = 24
- Divide by how many numbers (there are 3 numbers): 24 / 3 = 8
Why Does This Work?
It is because 6, 11 and 7 added together is the same as 3 lots of 8:
It is like you are "flattening out" the numbers
Example 2: Look at these numbers:
3, 7, 5, 13, 20, 23, 39, 23, 40, 23, 14, 12, 56, 23, 29
The sum of these numbers is 330
There are fifteen numbers.
The mean is equal to 330 / 15 = 22
The mean of the above numbers is 22
It is because 6, 11 and 7 added together is the same as 3 lots of 8:
It is like you are "flattening out" the numbers
Example 2: Look at these numbers:
3, 7, 5, 13, 20, 23, 39, 23, 40, 23, 14, 12, 56, 23, 29
The sum of these numbers is 330
There are fifteen numbers.
The mean is equal to 330 / 15 = 22
The mean of the above numbers is 22