Mostly Definitions Flashcards
What is an integer?
An integer is another name for a whole number - either a positive or negative number, or zero.
Integers: -365, 0, 1, 785
Not integers: 0.5, 2/3, -102.3, 6.6,
multiplying decimals - where does the decimal go?
4.6 x 2.7 = 1242
-start by ignoring decimal points and do the multiplication using whole numbers
46 x 27 = 1242
-count the total number of digits after the decimal points in the original numbers
4.6 x 2.7 - there are 2 digits after the decimal
-make the answer have the same number of decimal places
4.6 x 2.7 = 12.42
Alternate Angles
A pair of equal angles found in a ‘Z’ shape within two parallel lines.
Angle Bisector
A straight line that cuts an angle exactly in half.
Approximation
A number that is not exact because it has been rounded or estimated.
Back-to-back Stem and Leaf Diagram
A stem and leaf diagram where two sets are plotted on the same stem.
Bar Chart
A chart where the height of the bars shows the frequency of each category.
Bar-line Chart
A chart where the height of the lines shows the frequency of each category.
When you have an exponent, what is the base?
In a power, this is the number or letter which is multiplied by itself.
Biased
Where something, e.g. a dice or a spinner, is more likely to land on one or more of its sides than others.
BODMAS
An acronym to describe the order that operations should be done in a calculation containing multiple operations. Brackets, Other, Division, Multiplication, Addition, Subtraction
What is an ‘average’ and name 3 types of average.
A measure of the most typical value in a set of data. Mean, median and mode are types of average.
Median
The median is the middle number in a set of data, when the data has been written in ascending size order.
To find the median, put all numbers into ascending order and work into the middle by crossing off numbers at each end.
-In an odd-numbered set, the median will be the number in the very middle of the list.
-In an even numbered set, there will be two numbers in the middle. The median is the number that is half way between these two numbers. (Take the two middle numbers of the even-numbered set, add the two numbers together, divide the total by 2)
Mean
The mean is the arithmetic average of a set of given numbers. Therefore, the mean in math is often referred to as simply the “average.”
-Add all the scores together.
-Divide the sum by the number of scores used.
Mode
The mode is the most frequently occurring score in a set of given numbers. Put another way, it is the score that appears the greatest number of times.
-Look at all the data scores
-Identify the data score that appears most often
Range
The range of a data set is the difference between the greatest value and lowest value within a collection of numbers.
Subtract the smallest from the greatest value in the set to find the range of given data points.
What is a Prime Number?
A whole number greater than 1 that cannot be exactly divided by any whole number other than itself and 1 (e.g. 2, 3, 5, 7, 11).
2 is the only even prime number.
What is the net of a cube?
A cube is a symmetrical three-dimensional shape which consists of six square faces, twelve edges, and eight vertices. A net of a cube is a two-dimensional shape that can be folded into a three-dimensional figure.
(Essentially it is a square box which has been unfolded.)
Equilateral Triangle
Has 3 equal sides.
Isosceles Triangle
Has 2 equal sides.
Scalene Triangle
Has no equal sides.
Acute Angle Triangle
Has 3 angles less than 90 degrees.
Right Angle Triangle
Has one angle = 90 degrees.
Obtuse Angle Triangle
Has one angle greater than 90 degrees.
What is an acute angle?
An angle which is measuring less than 90 degrees
What is an obtuse angle?
An angle that measures more than 90 degrees and less than 180 degrees.
Reflex Angle
A reflex angle is any angle that is more than 180 degrees (half circle) and less than 360 degrees (full circle). A reflex angle will always have either an obtuse or an acute angle on the other side of it.
Angles in a quadrilateral add up to how many degrees?
360 degrees
Angles in a triangle add up to how many degrees?
180 degrees
What do we know about alternate angles in parallel lines (Z angles)?
They are equal.
What do we know about corresponding angles in parallel lines (F angles)?
They are equal.
What do we know about interior angles in parallel lines (C angles)?
They add up to 180 degrees.
Can a square number be a prime number?
No, all square numbers have an odd number of factors. A prime number has 2 factors, 1 and itself. Therefore no square can be a prime and no prime can be a square.
Odd numbers
Numbers ending with 1, 3, 5, 7 and 9.
Can’t be evenly divided.
Even Numbers
Numbers ending with 0, 2, 4, 6 and 8.
Can be evenly divided.
Write 140,000,000 in standard form.
140,000,000
=1.4 x 10^8
Factorise x^2 + 7x + 10
x^2 + 7x + 10
=(X +2) (x + 5)
*remember you need to find 2 numbers that multiply to 10 and add to 7.