Today We will see what is 
natural number? counting numbers are natural
number. what comes in your mind when we say
counting number simply what you count in your
daily life? like 1, 2, 3, 4, and soon. now
what is whole number? combining 0 with natural
number represents whole number. that means
the set of natural number along with zero,
that is 0 1 2 3 4 5 and so on is whole number.
so what is basic difference between natural
number and whole number. natural number starts
from 1 and goes on. but whole number contains
0 along with natural number. now what is number
line? we represent numbers on a line. you
can see over here its 0, 1, 2, 3, 4. every
number is equally spaced from previous one.
this number line will give a really futuristic
understanding of mathematics so in coming
future, we will see how we will use the number
line. now what is successor? adding one from
present natural number gives a successor number.
Now we will see by an example. what is successor
of 4? that means at present the number is
4 and we are finding successor. so we have
to add one in four. 4 + 1 equal to 5 so successor
of 4 is 5. now what is predecessor? similarly
subtracting 1 from present natural number
gives predecessor. now question is what is
predecessor of 7. That means we have to subtract
1 from 7. 7 minus 1 equal to 6. That is predecessor
of 7 is 6. Now its important point, Number
1 has no predecessor in natural number. Now
we know how to get predecessor. If we are
going to find the predecessor of 1, that means
we have to subtract 1 from present natural
number. that is 1 minus 1 is equal to zero
and 0 is not a natural number. so number one
has no predecessor in natural number.
