# Maths

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• Created by: ethscotty
• Created on: 06-04-15 14:16
• Maths - Immediate Learning Targets
• Data Handling
• Stratified Sampling
• Sample size for each layer = size of whole sample / size of population x size of layer
• There are 180 students in year 7- this is the size of the layer. There are 100 pupils in the school - this is the size of the whole sample, We need answers from 50 people in total - this is the size of the whole sampleIn order to find how many year 7 answers we take answers from, we do 50/1000 x 180 =9Answer = 9
• Combined Probability
• Make a table and work thing out logically.
• Histograms
• In a histogram, area = frequency
• Frequency Density = Frequency / Class width
• Number
• Indices
• 1 - Xm x Xn = Xm+n
• 2 - Xm / Xn = Xm-n
• 3 - (Xm)n =Xmn
• 4 - X0 = 1
• 5 - 1/Xn = X-n
• Standard Form
• The number is always written as A x 10n
• A is always between 1 & 10 and n is how many places the decimal moves
• 15,000,000 = 1.5 x 10 7
• Percentage Change
• For percentage increase or decrease, you form a  fraction of the two amount and multiply by 100
• Upper & Lower Bounds
• For the number 12, the lower bound is 11.5 and the upper bound is 12.5.
• Algebra
• Expanding One Bracket
• To expand, you need to multiply the part outside the brackets by every part inside the brackets e.g-3(x-6) = -3x +18
• Algebraic Fractions
• When adding or subtracting algebraic fractions, the first thing to do is to put them into a common denominator and then expand brackets
• To solve equations you must multiply both sides by a number/expression which removes the fraction
• Transformation of Functions
• Reflection over the x-axis :-f(x) reflects f(x) over the x-axis
• Reflection over the y-axis :f(-x) reflects f(x) over the y-axis
• Slide to the right or left :f(x+a) translates f(x) horizontally
• Slide upward or downward:f(x)+a translates f(x) vertically
• Horizontal stretch or compress:f(ax) stretches f(x) horizontally
• Vertical stretch or compress:af(x) stretches f(x) vertically
• Inequalitites
• The answer to an inequality is a range of numbers
• To solve inequalities, you must do to one side what you do to the other