very cheap answer
let's nevermind the decimal points for a second and just multiply 58 * 12, that's 696.
now, let's count the decimals on each, hmm 5.8 has 1 decimal number just .8 and 1.2 has also only 1 decimal number, just .2, so 5.8 has 1 decimal and 1.2 has one too, that's two decimals total, so we'll provide our answer with that many decimals, so 696 becomes 6.96.