Page 25 - Math 7
P. 25
Unit Number Systems in Different Bases
2
2.1 Whole numbers - Looking back
Classroom - Exercise
1. Let's tick () the correct numeral of the number name.
a) Seven lakh nine thousand: (i) 79000 (ii) 700900 (iii) 709000
b) Three crore six hundred: (i) 30006000 (ii) 30000600 (iii) 30060000
c) Eight million ninety-nine thousand: (i) 8099000 (ii) 899000 (iii) 8990000
d) If x is the digit at tens and y is at ones place, the number is:
(i) xy (ii) x + y (iii) 10x + y
e) The place name of five in 950038120 is:
(i) Ten-lakhs (ii) Crores (iii) Ten-crores
f) The place value of 9 in 20900470850 is:
(i) 90000000 (ii) 9000000 (iii) 900000000
2. Let's say and write the answers as quickly as possible.
a) The place name of 6 in 2460178953 in Nepali system is ................................
and in International system is ...........................................
b) Rewrite 5639240000 using commas and express in words in Nepali system.
............................................................................................................................
c) Rewrite 8719480000 using commas and express in words in International
system. ..............................................................................................................
Now, let’s study about the following sets of whole number and natural numbers.
W = {0, 1, 2, 3, 4, 5, ...} is the set of whole numbers. The set of natural numbers,
i.e. N = {1, 2, 3, 4, 5, ...} is a subset of the set of whole numbers.
Zero (0) is the least whole number, whereas 1 is the least natural number. The
greatest whole number or natural number is infinite.
2.2 Decimal or Denary number system
Hindu-Arabic number system is based on decimal or denary number system. In this
system, we use ten digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. Any whole number can be
written using a combination of these ten digits. The system is based on grouping of
tens. So, it is also known as the Base Ten or Decimal system.
Approved by Curriculum Development Centre, Sanothimi, Bhaktapur 23 Vedanta Excel in Mathematics - Book 7
