Give an example how to convert
$8.50 multiplied by 8 equal 68

If you're looking for a word problem here's one,

Nichole has $8.50 and she decides to invest it in to a company worth $1,000,000 in a year the company is worth $8,000,000 as the company went up in value so did Nichole's investment, how much was Nichole's Investment worth at the end of that year?

If your'e looking for someone to show the math here's that,

if you take the decimal first and multiply that by 8 you get 4 because 0.5*8=4, then you multiply the whole number and get 64 because 8*8=64, add the two together and you get 68, 64+4=68