Study Notes - Mathematics

 Today, in Mathematics we are making study notes of Number for our topic test on Friday. Now, I go to Mathematics site and we are talking about Number, Order of Operation, Rounding, Standard Form, Percentage "of mean times", Percentage increase/decrease, 

Number

• Multiples - Multiples are set of numbers that correspond to a base number that has been mulitplied by other numbers. A Multiple is formed by multiplying a given number by the counting numbers. 

Multiples: 3, 6, 9, 12...

• Factor - Factor is a number or algebraic expression that divides another number or expression evenly. Factors are the numbers you mulitply together to get a product.

Factor: 15 - 1, 3, 5, 15

• Prime Number - A Prime Number are numbers that have only 2 factors. A Prime Number is a number that can only be divided evenly (no remainders) by itself and the number 1.

• HCF (Highest Common Factor) - Highest Common Factor is found by finding all common factors of two numbers and selecting the largest one.

Highest Common Factor is 4.

8: 1, 2, 4, 8

12: 1, 2, 4, 6, 12

• LCM (Lowest Common Factor) - Lowest Common Factor is a multiple number you get when you multiply a number by a whole number. 

Lowest Common Factor is 24

6: 6, 12, 18, 24, 30, 36 ...

8: 8, 16, 24, 32, 40 ...

Order of Operation 

Here is what we did to solve problems and it's called BEDMAS: 

• B - stands for brackets.
• E - stands for exponents.
• D - stands for division.
• M - stands for multiplication.
• A - stands for addition.
• S - stands for subtraction.

Rounding 

Rounding means replacing a number with an approximate value that has a shorter, simpler, or more explicit representation.

 Example:

Replacing $23.4476 with $23.45, the fraction 312/937 with 1/3 or the expression √2 with 1.414.

Number	1dp	2dp	3dp
34.3565	34.4	34.36	34.357

Standard Form

Standard form allows us to write numbers without using as many digits. A number is standard form is written in two parts: Number from 1 to 9 x power of 10

Example: 

35 946 (first number must be from 1 - 9)

followed by power of 10

Answer: 3.5946 x 10 power of 4

Percentage (of mean times)

In mathematics, a percentage is a number or ratio expressed as a fraction of 100.

3/5 of 400 = 240

10% of 600 = 60

Increase/Decrease:

To Increase/Decrease an amount by a percentage, first calculate the percentage of the amount and then either add this answer on to increase the quantity, or subtract this answer to decrease the quantity.

Example:

Question	Working	Answer
Increase 60 by 10% Decrease 200 by 5%	60 + 10% * 60 200 - 5% * 200	66 190