$${\mathtt{2.997\: \!9}}{\mathtt{\,\times\,}}{{\mathtt{10}}}^{{\mathtt{8}}}{\mathtt{\,\times\,}}{\mathtt{6.626}}{\mathtt{\,\times\,}}{{\mathtt{10}}}^{-{\mathtt{34}}} = {\mathtt{0}}$$
.It is not 0 happy - it is just a very little number :)
2.9979x10^8 * 6.626x10^-34
=2.9979* 6.626x10^(8 -34)
=2.9979* 6.626*10^(-26)
$${\mathtt{2.997\: \!9}}{\mathtt{\,\times\,}}{\mathtt{6.626}} = {\mathtt{19.864\: \!085\: \!4}}$$
=19.8640854 x 10^-26
=1.98640854 x 10^-25