Math Flashcards
Ratio
An amount compared to another amount using : symbol
Simplify
Divide all parts of the ratio by a common factor
Direct proportion
2 or more quantities are in direct proportion if when one increases or decreases so does the other with the ratio of the quantities staying the same
Unitary method
Solving direct proportion problems by 1st calculating the value of a single item
At random
Describes a situation where the outcomes are equally likely
Mutually exclusive
2 outcomes are mutually exclusive if they can’t happen at the same time
Experimental probability
A probability estimated from data collected in an experiment
Theoretical probability
A probability found using equally likely outcomes
What’s the formula for the probability that an outcome doesn’t happen?
The probability that it doesn’t happen = 1 - p
Equally likely outcomes
When each outcome of an experiment occurs with equal probability
How can we find the number of possible outcomes?
Total number of equally likely outcomes = no. of outcomes of 1st item x no. of outcomes of 2nd item x …
What is the formula for relative frequency in probability?
Relative frequency = frequency / total throws
Why is repeating an experiment more reliable than repeating it for less times?
Because you will get better estimates of probabilities
Transform
Move a shape by reflection, rotation or translation; change a shape enlargement
Object
A shape before a transformation
Image
A shape after a transformation
Reflect
Transform a shape, producing the mirror image of that shape
Translate
Transform a shape by moving each part of the shape the same distance in the same direction
Rotate
Transform a shape, moving or turning each point of the shape around a fixed position through the same angle
Enlargement
A transformation that increases the size of a shape to produce a mathematically similar image
Combination of transformations
2 or more transformations carried out one after another
Scale factor
The ratio by which a length is increased
Centre of enlargement
The fixed point of an enlargement
pi
A mathematical constant approximately 3.14
Perpendicular height
The height of a shape or object measured at 90° to it’s base
Compound shape (or composite shape)
A shape made up of simpler shapes
What is the formula for the area of a triangle?
A = 1/2 bh
What does b stand for in area?
Base
What does h stand for in area?
Height
What height do we use to find the area of a triangle, parallelogram and trapezium?
The perpendicular height
What is the formula for the area of a parallelogram?
A = bh
What is the formula for the area of a trapezium?
A = 1/2(a + b)h
What is the plural word for trapezium?
Trapezia
What is the formula for the circumference of a circle if we are given the diameter?
C = πd
What is the formula for the circumference of a circle if we are given the radius?
C = 2πr
What is the formula for the circumference of a semicircle?
C = 1/2πd + d
What is the formula for the circumference of a quarter circle?
C = 1/4(2πr)
What is the formula for the area of a circle?
A = πr²
What is the formula for the area of a semicircle?
A = 1/2(πr²)
What is the formula for the area of a quarter circle?
A = πr² /4
How do we find the area of compound shapes?
- Divide the shape into simple shapes
- Work out the area of each simple shape
- Add or subtract the area of the simple shape to get the area we need
What is the formula for the volume of cuboids?
V = lwh
What is the formula for the surface area of cuboids?
SA = 2lw + 2lh + 2wh
Circumference of a circle/perimeter or the circle
A line made up of points that are the same distance from the center
Radius of a circle
A line that joins the center of a circle to any point or the circumference
Diameter of a circle
A line that joins two points of the circumference. It’s 2x the radius
Arc
Part of the circumference
The sector of a circle
The area enclosed between two radii and an arc
Chord
A line segment that joins 2 points on the circumference of a circle
Segment
An area enclosed between a chord and arc
