Hi Mahaveer,

My first observation with your number, "four and two sixths" is that $\large \frac26$ can be simplified. $2 = 2 \times 1$ and $6 = 2 \times 3$ and hence

\[\frac26 = \frac{2 \times 1}{2 \times 3} = \frac13\]

Hence $4 \frac26 = 4 \frac13$ which is four and a fraction. To express the fraction divide the denominator into the numerator. Thus for example to convert $7 \frac56$ into a decimal divide $6$ into $5$ to get $0.833$ to three decimal places and hence $7 \frac56 = 7.833.$

Penny