Why do I get the result 0 when I input 35^2 / (8.574 * 10^10)^2 to the calculator? I should get approx. 1.7 * 10^-19

Okay the calc does give you 0

 

$${\frac{{{\mathtt{35}}}^{{\mathtt{2}}}}{{\left({\mathtt{8.574}}{\mathtt{\,\times\,}}{{\mathtt{10}}}^{{\mathtt{10}}}\right)}^{{\mathtt{2}}}}} = {\mathtt{0}}$$

 

Lets have a look by breaking it up

$${{\mathtt{35}}}^{{\mathtt{2}}} = {\mathtt{1\,225}}$$

$${{\mathtt{8.574}}}^{{\mathtt{2}}} = {\mathtt{73.513\: \!476}}$$

$$=\frac{1225}{73.513476\times 10^{20}}
=\frac{1225\times 10^{-20}}{73.513476}$$

 

$${\frac{{\mathtt{1\,225}}}{{\mathtt{73.513\: \!476}}}} = {\mathtt{16.663\: \!611\: \!444\: \!519\: \!369\: \!5}}$$

 

$$\\=\frac{1225}{73.513476\times 10^{20}}\\
=\frac{1225\times 10^{-20}}{73.513476}\\
=16.6636\times 10^{-20}\\
=1.66636\times 10^{+1}\times 10^{-20}\\
=1.66636\times 10^{-19}\\$$

 

okay, this is NOT zero  the calculator called it zero because the number is tiny.  Too tiny for the calc to display properly.