Mathematical expressions are
often needed when giving a technical presentation. Click on the
links below for explanations of each point.
Addition
Subtraction
Multiplication
Division
is the symbol for ADDITION and is called the PLUS
sign.
Related expressions
are:
INCREASED
BY
and
THE
SUM OF
-
e.g.
3 +
4 is read as 'three plus
four'
or
'three increased by four'.
The answer to the problem
(seven), is called THE
SUM of the two numbers.
e.g.
3 +
4 = 7
can be read as:
'THE SUM OF three and four is seven'.
The plus sign is also
used to contrast a positive number with a negative number
e.g.
+2
> -5
is read as:
'plus
two is greater
than minus
five'
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is the SUBTRACTION symbol and is called the MINUS sign.
Related expressions
are:
DECREASED
BY
DIFFERENCE
and
LESS.
e.g.
5 -
3
is usually read as
'five minus three',
but it can be read
as
'five decreased by three'
or
'five less three'.
The answer to the problem
(two) is called the DIFFERENCE between the two numbers.
- 5 is usually read as 'minus
five',
but it can be read
as
NEGATIVE five
or
the ADDITIVE INVERSE of five.
is read as PLUS OR MINUS five.
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The symbols for MULTIPLICATION are as follows:
x as in the expression 3 x 7
One or two pairs of:
PARENTHESES (x)(7)
BRACKETS
x[7]
or
BRACES {x}7
Two or more letters
xy
or a number and one
or more letters next to each other with no space between them
as below:
2ax
5xy
These are the symbols
for MULTIPLICATION.
Related expressions
are:
MULTIPLY
BY
TIMES
MULTIPLIER
and
FACTOR
e.g.
7 x
3
can be read as 'seven
multiplied
by three'
or
'seven times three'.
The 3
and the 7
are the
MULTIPLIERS
or
FACTORS.
The answer to the problem
(twenty-one) is called the
PRODUCT.
The word 'of' sometimes means 'multiplied by' as in the following expressions:
'Half of twenty is ten' (1/2
of 20 = 10)
'Twenty per cent of fifty is ten' (20% of 50 = 10)
There are other ways
to express multiplication:
6 x
3 can be expressed as 'six increased by a
factor of three'
2x can be expressed as 'double x' or 'twice x'
2 x
4 can be expressed as 'two by four'
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is read as 'divide by'
e.g.
is read as 'eighteen divided by six'
This symbol is read
as 'divide
into'
This is read as 'four divided into twenty-four'
This is read as 'a over b'
XX-IT IS NOT READ AS 'a by b'-XX
Related expressions
are:
DIVIDEND,
DIVISOR
and
QUOTIENT.
The equation above
is read as:
'eighty-one over six equals thirteen
point five'
The number 81 is the DIVIDEND
(the number divided into)
The number 6 is the DIVISOR
( the number divided by)
The answer to the equation,
13.5, is the QUOTIENT
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Relational
Symbols
Decimals,
Fractions, Ratios
Roots,
Exponentiation
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