NCERT Solutions for Class 8 Maths – Ganita Prakash
Chapter: A Story of Numbers
Exercise 3.4
1. Represent the following numbers in the Egyptian system:
Egyptian symbols used:
- | = 1
- ∩ = 10
- spiral = 100
- lotus = 1000
- finger = 10000
(i) 10458
10458 = 10000 + 400 + 50 + 8
So, in Egyptian system:
1 symbol of 10000, 4 symbols of 100, 5 symbols of 10, and 8 symbols of 1
(ii) 1023
1023 = 1000 + 20 + 3
So, in Egyptian system:
1 symbol of 1000, 2 symbols of 10, and 3 symbols of 1
(iii) 2660
2660 = 2000 + 600 + 60
So, in Egyptian system:
2 symbols of 1000, 6 symbols of 100, and 6 symbols of 10
(iv) 784
784 = 700 + 80 + 4
So, in Egyptian system:
7 symbols of 100, 8 symbols of 10, and 4 symbols of 1
(v) 1111
1111 = 1000 + 100 + 10 + 1
So, in Egyptian system:
1 symbol of 1000, 1 symbol of 100, 1 symbol of 10, and 1 symbol of 1
(vi) 70707
70707 = 70000 + 700 + 7
So, in Egyptian system:
7 symbols of 10000, 7 symbols of 100, and 7 symbols of 1
2. What numbers do these numerals stand for?
(i)
Count the symbols:
- 2 spirals = 2 × 100 = 200
- 6 symbols of 10 = 6 × 10 = 60
- 7 symbols of 1 = 7 × 1 = 7
Total = 200 + 60 + 7 = 267
(ii)
Count the symbols:
- 4 symbols of 1000 = 4 × 1000 = 4000
- 3 spirals = 3 × 100 = 300
- 2 symbols of 10 = 2 × 10 = 20
- 2 symbols of 1 = 2 × 1 = 2
Total = 4000 + 300 + 20 + 2 = 4322