Calculation Error

"Show me again, Mr Kenton." sighed the president, still trying to understand what exactly was being explained to him.

"Ok." said the other man. He slowly typed the buttons on the calculator.
"Two.....multiplied by.....eight.....equals......There! Seventeen!"

The President gave him a blank look.

"Apparently Sir, the answer is actually Sixteen."

"And you're sure these men are right? I mean, they do their calculations on paper using no electronic devices for goodness sake!"

"I can assure you, sir, their methods were used several hundred years ago, and have been proved to be one hundred percent accurate".

"So what exactly does this mean?" asked the President.

"Well, sir," muttered Kenton, now in a very nervous voice, "as you know we launched our first colonization ship last week."

"Ah, yes." replied the President proudly, "All of the most important members of our society, sent off to ensure the continuation of the human race on a newly discovered planet just like earth."

"Well that's the thing, Sir", Kenton continued, now visibly sweating. "The navigation computers all use the same technology as this humble calculating machine. So if this is slightly out on its calculations, a navigational calculation requiring accuracy to hundreds of decimal places....."