Concept : 1 Mark
Process : 1 Mark
Conclusion : 1 Mark
169 - 1 = 168
168 - 3 = 165
165 - 5 = 160
160 - 7 = 153
153 - 9 = 144
144 - 11 = 133
133 - 13 = 120
120 - 15 = 105
105 - 17 = 88
88 - 19 = 69
69 - 21 = 48
48 - 23 = 25
25 - 25 = 0
Thus, in case of 169, we need to take 13 steps to get zero by successive subtractions.
∴√169=13.