Find the square root of $196$ by repeated subtraction ?

196 - 1 = 195
195 - 3 = 192
192 - 5 = 187
187 - 7 = 180
180 - 9 = 171
171 - 11 = 160
160 - 13 = 147
147 - 15 = 132
132 - 17 = 115
115 - 19 = 96
96 - 21 = 75
75 - 23 = 52
52 - 25 = 27
27 - 27 = 0.
[0.25 $\times$ 14 = 3.5 marks]

So, $14$ consecutive odd numbers are repetedly subtracted from $196$ to get 0.
Hence, <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> $\sqrt{196}$ = 14.
[0.5 marks]