marked before and after the number. In Braille, the reverse (t), that is dots 1,2,5 and 6 are
placed in the first cell followed by the number and then inserting the dots 1,2,5 and 6 in
the third cell indicates the absolute value. In matrices too, this symbol is used. For
example,
3 is written as5 6
2 4
(^) is written as
Base Code 25: Dots 1, 2, 3, 4 and 6 - Mirror image of (y)
Factorial
In algebra, an expression called factorial is used. It is indicated by the visual symbol (!),
which is an exclamatory mark in English braille. While dots 2,3, and 6 are used in literary
Braille to indicate the exclamation mark (!), the expression “factorial” in Mathematics (!)
is indicated by the reverse (y). 5 !, n !, etc., are written in Braille as follows.
5! - n! -
Factorial is a concept not very much used at the secondary level mathematics. However,
there is a need for the learner to understand the descriptions of all base codes.
Base Code 26: Dots 2, 3, 4 and 6 - Mirror image of (z)
Integral Sign
In Calculus, the expression “integral” is used. For more description of the terminology,
refer to the instructional materials. The integral sign is written singularly or in multiple
ways. For indicating a single integral sign, reverse (z), that is dots 2,3,4 and 6 are used.
For indicating a double integral, two cells are used. Please see the examples below:
∫ ∫∫ ∫∫∫
-.
••.
..
••..-.
••.
- -.
••.
..
-.
-.
..
••.- -.
••.- -.
••.
- -.
..
..
..
••-.
-.
••.
..
..
••.
- -.
.•
.•
••..
.•
.•.•
-.
••
.•
-.
••
.•
-.
••
.•
-.
••
.•
-.
••
.•
-.
••
••
-.
••
••
-.
••