Page 164 - Math Skill - 4

162 Maths

Let us see how each letter has been coded here.

A B C D E F G H I J K L M

1 2 3 4 5 6 7 8 9 10 11 12 13

N O P Q R S T U V W X Y Z

14 15 16 17 18 19 20 21 22 23 24 25 26
HAVE FUN coded as 8 1 22 5 6 21 14

MATHEMATICS coded as 13 1 20 8 5 13 1 20 9 3 19

Other codes substitute letters with other letters. Instead of writing A, write Z. Similarly for B
st
th
nd
th
write Y, that is instead of the 1 letter, write the 26 letter, instead of the 2 , write the 25 letter.
th
rd
So, instead of C, which is the 3 letter, we have to write X, which is the 24 letter.
HAVE FUN coded as SZEV UFM
MATHEMATICS coded as NZGSVNZGRXH

Exercise 12.3

1. If A—1, B — 2, C—3,.................. X—24, Y—25 and Z—26, then write the messages for each
of the following.
(a) 9 12 15 22 5 13 1 20 8
(b) 8 15 13 5 19 23 5 5 20 8 15 13 5

(c) 13 25 13 15 20 8 5 18 9 19 2 5 19 20

2. Using the same code as given above rewrite the following.
(a) BE HAPPY ____________________________________________
(b) TODAY IS HOLIDAY ____________________________________________

Symmetry
Symmetry occurs when an object or shape looks
exactly the same on both sides of an imaginary line.

We see various objects and figures in our daily life.
Some are symmetrical and some are not symmetrical.
Observe that in both the figures the two parts on
both the sides of the dotted line are exactly identical.

Such figures are said to be symmetrical and the
dotted line is called the line of symmetry or axis of
symmetry.
Some objects like the ones given below are not
symmetrical. They are called non-symmetrical
objects.