Download Maths vocabulary Shape Dictionary

Maths Vocabulary
Angles
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Acute angle - An angle greater than 0o and less than 900
Angle at a point -The complete angle all the way around a point is 360o
Angle on a straight line -The sum of the angles at a point on a line is 180o
Right angle = 90o
Obtuse angle – an angle greater than 900 and less than 180o
Reflex angle – an angle greater than 180o and less than 360o
Area and Perimeter
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Area - A measure of the space inside a 2D shape. Area is usually measured in square units e.g.
square centimetres (cm2 ), square metres (m2 ). For a rectangle you can multiply the width x
length to get the area.
Perimeter – a measure of the length around the shape – add up the lengths of all the sides.
Averages
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Mean - The sum of a set of numbers divided by the number of terms in the set. Example: The
mean of 5, 6, 14, 15 and 45 is (5 + 6 + 14 + 15 + 45) ÷ 5 = 17.
Mode – The most commonly occurring value or class with the largest frequency. e.g. the mode
of this set of data: 2, 3, 3, 3, 4, 4, 5, 5, 6, 7, 8 is 3 Some sets of data may have more than one
mode.
Median – The middle number or value when all values in a set of data are arranged in ascending
order. Example: The median of 5, 6, 14, 15 and 45 is 14. When there is an even number of
values, the arithmetic mean of the two middle values is calculated. Example: The median of 5, 6,
7, 8, 14 and 45 is (7 + 8) ÷ 2 i.e. 7.5.
Range - The difference between the greatest value and the least value in a set of numerical data.
Measure
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Capacity - the volume of a material (typically liquid or air) held in a vessel or container.
Measured in litres, millilitres, cubic cms and cubic ms
1 litre = 1000 millilitres
1km = 1000m
1m = 100 cm
1cm = 10 mm
1kg = 1000g
Time
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12 hour clock – uses am or pm to show morning and afternoon / evening
24 hour clock – doesn’t use am or pm and uses 13.00, 14.00…to show afternoon / evening
1 year = 365 days (366 in a leap year)
1 year = 12 months
1 month = roughly 30 days or 4 weeks
1 week = 7 days
1 day = 24 hours
1 hour = 60 minutes
1 minute = 60 seconds
30 days has September, April, June and November, all the rest have 31, except February alone
which only has but 28 days clear, and 29 in each leap year
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Maths Vocabulary
Shape
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Composite shape - A shape formed by combining two or more shapes e.g. two rectangles
together.
Concave – curving inwards
Convex – curving outwards
Edge - A line joining two vertices of a shape. A line formed by the intersection of two surfaces.
Examples: a square has four edges; and a cuboid has twelve edges.
Equilateral triangle – all three sides are equal, all angles are equal.
Isosceles triangle - A triangle in which two sides have the same length and two angles are equal.
Face - One of the flat surfaces of a solid shape. Example: a cube has six faces; each face being a
square
Horizontal - Parallel to the horizon.
Perpendicular – a line at right angles to another one
Parallel – Parallel lines that never meet however far they are extended – like train tracks – the
distance between them remains the same.
Vertical – At right angles to the horizontal plane. The up-down direction on a graph or map
Quarter turn – turn through 90o
Half turn – turn through 180o
Three quarter turn – turn through 270o
Translation – slide the shape to its new position – don’t change the shape
Rotate around a point – turn the shape around a fixed point (maybe around the origin (0,0) on
your graph axis
Reflect – use a mirror to flip the shape
Factors and multiples
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Factor – 2 numbers that can be multiplied together to form another number. Examples: 1, 2, 3,
4, 6 and 12 are all factors of 12 because 12 = 1 × 12 = 2 × 6 = 3 × 4. Think about them as factor
pairs.
Common factor - A number which is a factor of two or more other numbers, for example 3 is a
common factor of the numbers 9 and 30
Common multiple – A number which is a multiple of a given set of numbers, e.g. 24 is a common
multiple of 2, 3, 4, 6, 8 and 12.
Multiple – when 2 factors are multiplied together the answer is a multiple e.g. 15 is a multiple of
3 and 5
Prime number - A whole number greater than 1 that has exactly two factors, itself and 1.
Examples: 2 (factors 2, 1), 3 (factors 3, 1). 51 is not prime (factors 51, 17, 3, 1).
Number
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Equal – the same on both sides
Even – a number that is divisible by 2 leaving a whole number e.g. 2,4,6,8
Odd – a number that cannot be divided by 2 to leave a whole number e.g. 1,3,5,7,9
Squared – e.g. 52 = 5 x 5 = 25
Square root - A number whose square is equal to a given number. Example: one square root of
25 is 5 since 52 = 25.
Cubed – e.g. 53 = 5 x 5 x 5 = 125
The inequality signs in use are:
≠ means ‘not equal to’; A ≠ B means ‘A is not equal to B”
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Maths Vocabulary
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< means ‘less than’; A < B means ‘A is less than B’
> means ‘greater than’; A > B means ‘A is greater than B’
≤ means ‘less than or equal to’; A ≤ B means ‘A is less than or equal to B’
≥ means ‘greater than or equal to’; A ≥ B means ‘A is greater than or equal to B’
Integer – Any of the positive or negative whole numbers and zero. Example: …- 2, -1, 0, +1, +2 …
Product – the result of multiplying one number with another
Quotient – the result of a division e.g. 45 divided by 3 – the quotient is 15
Order of operation - Generally, multiplication and division are done before addition and
subtraction, but brackets can be used to indicate calculations that must be done before the
remainder of the operations are carried out.
Fractions
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Improper fraction - An improper fraction has a numerator that is greater than its denominator.
Example: 9 /4 is improper and could be expressed as the mixed number 2¼
Denominator – the number on the bottom of a fraction (how many equal parts something is
being divided into)
Numerator – the number on the top of a fraction (how many equal parts of something are being
used)
Mixed number - A whole number and a fractional. Example: 2 ¼ is a mixed number.
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