Need help with Multiplying Interegers' ciphers

[daduna]

hello, i need to multiply integer ciphers, and dont know how,
for examlpe:
int a =234;
i need to do 2 * 3 * 4 = 24 and then cout result :)

[daduna]

//234
// (a % 10) * (((a % 100)-(a%10))/10) * (a/100)

I solved this for Int, but this wont work for Double