Phil Phillips sat at his desk calculating: 49+5599+766+65=6,879. "I love to draw the +," said thrifty Phil, "I also like the =". It is the - that I don't like that much. He then flicked through his reports and receipts. "Where is the Fileman report?" he called out in the office. 

Phil wrote the monthly financial report for his company. It read: "This month's income will be up 33 per cent from this month last year. It will also be up 5 per cent from the 4th quarter and the quarter before. This means that the total increase in sales 
is +/- 9 per cent for the year. Our pre-tax profit is currently at 89,599.87 dollars." 

Phil was very satisfied with the +9 per cent increase in sales. His 4 years old gerbil selling business was going really well. He dreamed of the day he could open more stores. Maybe even 57. What he really wanted, was to be the first gerbil selling franchise 
listed in the Top 499 companies of the year. 

He went to his computer to send out e-mails about the sales 
figures. Phil now happily entered the numbers into his 
computer: 999+4,999= 5,998. 555-56=499. 499+467=966. 966+5,998=6,964. Then what? -64+44+(75/68)/5-889=? How difficult can it get? 
