Write the following in decimal form and say what kind of decimal expansion each has :
$(i)$ $\frac{36}{100}$
$(ii)$ $\frac{1}{11}$
$(iii)$ $4 \frac{1}{8}$
$(iv)$ $\frac{3}{13}$
$(v)$ $\frac{2}{11}$
$(vi)$ $\frac{329}{400}$
$(i)$ $\frac{36}{100}=0.36$
Terminating
$(ii)$ $\frac{1}{11}=0.090909 \ldots \ldots=0 . \overline{09}$
Non-terminating repeating
$(iii)$ $4 \frac{1}{8}=\frac{33}{8}=4.125$
Terminating
$(iv)$ $\frac{3}{13}=0.230769230769 \ldots .$$=0 . \overline{230769}$
Non-terminating repeating
$(v)$ $\frac{2}{11}=0.18181818 \ldots \ldots .$$=0 . \overline{18}$
Non-terminating repeating
$(vi)$ $\frac{329}{400}=0.8225$
Terminating
Show that $3.142678$ is a rational number. In other words, express $3.142678$ in the form $\frac {p }{q }$, where $p$ and $q$ are integers and $q \ne 0$.
Write three numbers whose decimal expansions are non-terminating non-recurring.
Rationalise the denominator of $\frac{1}{2+\sqrt{3}}$.
Rationalise the denominator of $\frac{1}{7+3 \sqrt{2}}$
Add $2 \sqrt{2}+5 \sqrt{3}$ and $\sqrt{2}-3 \sqrt{3}$