Maths terms

acute angle (noun): any angle measuring between 0° and 90° – The leaves protrude out of the stem at an acute angle.

add (verb): to combine two numbers to get a total – If we add 2 to 4, we get 6.

addition (noun): the bringing together of two or more numbers to find a total – The addition of 2 new students to the class of 20 brought the total number of students to 22.

ALGEBRA (noun): a branch of mathematics in which letters and other symbols can be used to represent numbers – It wasn't until I studied algebra that I got the concept of E = mc².

algorithm (noun): a set of rules used to carry out any calculation – Following this algorithm will make the problem easier to solve.

angle (noun): the space (measured in degrees) between two lines which meet at a certain point – A square has four angles, whereas a triangle has three.

arc (noun): a curved shape, the distance between any two points on the of the circumference of a circle – The sun moved in an arc across the cloudless sky from sunrise to sunset.

area (noun): the two-dimensional space occupied by an object or shape – Malta is a small country with a surface area of 316 km².

ARITHMETIC (noun): the oldest and most basic branch of maths, dealing with numbers and their basic operations: addition, subtraction, multiplication, and division – There were 10 students in one class and 15 in the other, which if my arithmetic serves me right comes to 25 in total.

ascending order (noun): increasing; arranged from smallest to largest – They told us to line up in ascending order of height, with the shortest on the left.

average (noun): a mean; a number that is a typical representation of a set of numbers – To calculate the average of four different numbers for example, simply add the four numbers, then divide the total by four. So the average of 2, 4, 6 and 8 is 20 divided by 4 which is 5.

axis (noun): an imaginary straight line around which a body rotates – The earth rotates on its axis which runs from North Pole to South Pole.

base (noun): in geometry a base is the bottom line of a 2D shape such as a square or triangle, or the bottom surface of a 3D shape such as a pyramid – The statue stood on a heavy stone base.

binary (adjective): relating to a system of numbers based on 2. See decimal – Computers use a "base-2" binary system of numbers 0 and 1.

CALCULUS (noun): a branch of mathematics that studies continuous rates of change – Astronomers use calculus to track the orbits of different planets.

capacity: (noun): the maximum volume that a container can hold – The tank has a capacity of 64 litres.

cardinal number (noun): a number that expresses quantity (one, two, three etc), as opposed to an ordinal number which expresses position (first, second, third) – We started the lesson by learning about cardinal numbers.

circle (noun): see shapes

circumference (noun): The boundary of a circle or other curved geometric figure – The circumference of the wedding cake was 140 centimetres.

common fraction (noun): a fraction expressed as a numerator above and denominator below, for example ½ (as opposed to decimal 0.5). Also called vulgar fraction – In practice, common fractions are often simply called fractions.

cone (noun): see shapes

consecutive numbers (noun): whole numbers that follow each other in ascending order without gaps – We can say that 7, 8, 9, 10, 11, 12 are consecutive numbers but 7, 9, 12 or 12, 8, 11 are not.

coordinates (noun): usually a pair of numbers indicating a point on a graph (or map etc) – We read the first coordinate along the graph (left to right) and the second coordinate up the graph (bottom to top).

cube (verb): when you cube a number you multiply it by itself three times – If you cube 3 you get 3³ = 3 x 3 x 3 = 27. Three cubed is twenty-seven.

cube (noun): see shapes

cube root (noun): the cube root of a number is the factor that we multiply by itself three times to get that number. – 3 × 3 × 3 = 27 so the cube root of 27 is 3. The cube root of 8 is 2 because 2 x 2 x 2 = 8.

curve (noun): a line that flows smoothly without any sharp turns – In maths a curve can be a straight line.

cylinder (noun): see shapes

decimal (adjective): relating to a system of numbers based on 10. This "base-10" system of numbers using 0-9 is derived from the Hindu-Arabic number system – Computers don't work with decimal numbers: they have to convert them into binary first.

decimal point (noun): A full point or dot placed after the figure representing units in a decimal fraction – In English the decimal point is like a period (12.5) but in some languages, French for example, the decimal symbol is a comma (12,5).

degree (noun): a unit of measurement for angles. The symbol is °. There are 90° in a right angle (an interior corner of a square) – Any angle less than 90° is called an acute angle.

denominator (noun): The number below the line in a vulgar fraction – The teacher pointed to the denominator at the bottom of each fraction on the board.

descending order (noun): decreasing; arranged from largest to smallest – Our exam scores were listed in descending order with the best at the top.

diagonal (noun): a line that connects any two corners, but is not an edge – If you have a square and you join the top left corner to the bottom right corner, you get a diagonal.

diameter (noun): The measurement of the longest distance across a circle, from one point to another – The table is over a metre in diameter and can easily seat four people.

digit (noun): any of the ten Arabic numerals from 0 to 9 – The number 9 has only one digit, whereas 11 and 12 both have two digits.

divide (verb): to break up a number into equal parts. We use the symbol ÷ (or the symbol / ) to mean divide – We write 12 ÷ 3 = 4 and we say twelve divided by three equals four. We can also write 12 / 3 = 4.

division (noun): The process of breaking up a number into equal parts. It is the opposite of multiplication. Division is represented by the ÷ symbol – The division of the class into four groups of 3 meant that we all got a chance to speak.

edge (noun): a line between corners in 2D and 3D shapes – A square has four edges and a cube has 12 edges.

equal sign (noun): the symbol = indicating that two amounts are of the same value, for example 2 + 2 = 4 – I wrote down the answer on the right side of the equal sign.

equation (noun): A mathematical statement which uses an equal sign ( = ) to indicate that two mathematical expressions are of the same value – The most famous equation ever is probably Einstein's E = mc².

equilateral (adjective): having all sides the same length – By definition all squares are equilateral, but other shapes can be equilateral too.

even number (noun): any integer (never a fraction) that can be divided exactly by two – The houses on the right side of the road all have even numbers | 2 and 4 are even numbers, whereas 1 and 3 are odd numbers.

factor (noun): a number which produces another number when it is multiplied – Both 2 and 3 are factors of 6.

formula (noun): a mathematical rule that can be written with numbers, letters and symbols – The formula V = l x w x h will give the volume of a box where V = volume, l = length, w = width and h = height.

fraction (noun): a numerical representation of equal parts of a whole. If you cut a whole orange into two equal pieces, each piece is a fraction of the whole and can be expressed as 0.5 (decimal), ½ (common fraction), or 50% (percentage) – After the hungry children had finished their lunch, only a fraction of the pie remained.

geometric, geometrical (adjective): relating to geometry – Much ancient Greek pottery was characterized by geometric patterns.

geometry (noun): the branch of mathematics dealing with points, lines, surfaces, solids etc – I have a geometry test tomorrow.

graph (noun): A diagram expressing the relationship of a set of numbers or measurements, usually with lines – The seasonal temperatures were shown on a graph with a single line going up and down.

greater than: the symbol > means greater than or bigger than. See also < less than – If we write 5 > 3 we are saying that five is greater than three.

hemisphere (noun): half of a sphere or three-dimensional round object – The earth's northern hemisphere and southern hemisphere are separated by the equator.

infinity (noun): in maths, an imaginary number that is greater than any countable number; the symbol for infinity is ∞ – The infinity symbol is a closed figure of eight loop on its side indicating its unending nature.

integer (noun): A whole number with no fractional parts – 3 is an integer, whereas 3.5 is not.

less than: the symbol < means less than or smaller than. See also > greater than – If we write 3 < 5 we are saying that three is less than five.

mean (noun): see average

minus (preposition): with the subtraction of – Does 25 minus 10 equal 15?

minus sign (noun): the symbol ( - ) indicating subtraction or a negative value – An example of the minus sign for subtraction is 5 - 3 = 2. An example of the minus sign for a negative value is that -10℃ is ten degrees below freezing.

multiplication (noun): the process of taking a number and adding it together multiple times. Multiplication is represented in expressions by the times symbol ( x ) – An example of multiplication is four times three ( 4 x 3 ) which is the same as 4 + 4 + 4 = 12.

multiply (verb): to apply multiplication; to take a number and add it together multiple times – If you multiply 3 by 4, you get 12.

negative number (noun): a number that is less than zero, typically preceded by a minus sign ( - ) or sometimes written in red – In 2 - 5 = -3, the result is a negative number.

numerator (noun): the number above the line in a common or vulgar fraction – In ⅔ the numerator is 2 and the denominator is 3.

obtuse angle (noun): an angle that is greater than 90° but less than 180° – The door was wide open at an obtuse angle.

odd number (noun): any whole number that cannot be divided exactly by two. See even number – The number 23 is an odd number because it cannot be divided by 2.

ordinal number↗ (noun): a number indicating the position of something within a list. Ordinal numbers show the "order" of things. They can be written in full (first, second, third etc.) or abbreviated (1st, 2nd, 3rd) – Unfortunately my horse came in third so I lost my money. | She was born on the 2nd of May.

oval (noun): see shapes

parallel (adjective): (of two lines) placed side by side with an equal distance between them at all points – The two planks of wood ran parallel to each other on the floor. Parallel lines never meet.

percent (adverb): parts per hundred. The symbol is % – We sleep for about 30% of our lives.

perimeter (noun): the total distance around a two-dimensional shape. The perimeter can usually be calculated by adding the length of all the edges together – Each edge of this square is 10cm, so the perimeter is 40cm.

plus sign (noun): the symbol ( + ) placed between two numbers to indicate that the second number is being added to the first – An example of the plus sign for addition is 5 + 3 = 8, spoken as five plus three equals eight.

pi (noun): the ratio of a circle's circumference to its diameter (circumference divided by diameter). Pi is approximately 3.14159 and is represented by the Greek symbol π – I calculated the circle's circumference by multiplying its diameter by pi. The value of pi is always the same regardless of a circle's size.

polygon (noun): see shapes

prime number (noun): a whole number greater than 1 that cannot be exactly divided by any whole number except itself and 1 – Four can be divided by 2, so it is not a prime number. Seven can only be exactly divided by 1 and 7, so it is a prime number.

PROBABILITY (noun): a branch of mathematics that predicts how likely something is to happen – When we toss a coin, the probability of it landing heads up is 50%.

radius (noun): a straight line representing the distance from the centre of a circle to its circumference – The radius of the circle is half the length of the diameter.

ratio (noun): a comparison of the quantity of one thing with the quantity of another thing – In our school there are 3000 students and 100 teachers, so the ratio of students to teachers is 30 to 1 (also written as 30 : 1).

rectangle (noun): see shapes

remainder (noun): an amount left over after division when the first number cannot be divided exactly by the other – 4 goes into 10 two times with the remainder of 2.

right angle (noun): an angle measuring exactly 90°, such as an interior corner of a square. – If you draw a triangle with sides that are 3, 4 and 5 units in length, then you can create a perfect right angle using just a ruler.

round up/down (verb): if you round a number, you make it simpler to use but keep it close to its original value - For example, you might round 43 down to 40. And you might round 47 up to 50.

sphere (noun): see shapes

square (noun): see shapes

square root (noun): a number's square root (symbol √ ) is a smaller number whose product is the original number when multiplied by itself – The square root of 9 is 3 ( √9 = 3 ).

subtract (verb): to take one amount or quantity away from another – If you subtract 3 from 10, you get 7.

subtraction (noun): the process of subtracting one number from another. We use the minus sign ( - ) to indicate subtraction in maths – We practised our subtraction by removing pennies from the pile on the table.

sum (noun): the amount which results from the addition of two or more numbers – 7 is the sum of 1, 2 and 4.

three-dimensional, 3D (adjective): having 3 dimensions: length, breadth, depth. See 2D – Objects like boxes and buildings are 3D.

times sign (noun): the symbol ( x ) that indicates multiplication – In multiplication we write 2 x 3 = 6 and say two times three equals six (or two multiplied by three equals six).

triangle (noun): see shapes

TRIGONOMETRY (noun): the branch of mathematics that studies triangles, their angles and lengths etc – Astronomers use trigonometry to figure out the distance of stars from earth.

two-dimensional, 2D (adjective): having two dimensions: length, breadth. See 3D – Flat shapes like a triangle or a piece of paper are basically 2D.

volume (noun): the amount of space occupied by any three-dimensional object, or that a three-dimensional object can contain; capacity – Three-dimensional objects have volume whereas two-dimensional objects have area.

whole number (noun): integer; any number without fractional or decimal parts – 7 and 51 are whole numbers but 7½ and 51.3 are not.