Hands-on math!

Washington State Math Olympiad
Hints and Solutions
2006 Grade 8 Number Sense
Problem
1) The Monday after Thanksgiving is now called "Cyber Monday" and is the busiest on-line shopping day of the year. On Cyber Monday 2004, credit card users for one company spent 4/5 the amount of money they spent on Cyber Monday in 2005. What percent more money was spent in 2005?
2) Solve for N in the following equation.

3) Joji Kato set a world record in the 500 meter speed skating race at Salt Lake City. He finished in 34.30 seconds. If he could keep the same speed for the 10,000 meter speed skating race, how many minutes and seconds would it take him to finish the race?

Problem
4) What is the one's digit of 826?

5) An alien species has 3 "fingers" on each "hand". They visit a school while on a friendship mission. The children discover the aliens also use the digits 0, 1, 2, 3, 4, and 5 and that they mean the same thing but they don't use the digits 6 - 9. When they multiply 4x5 they get 32. The teacher says they are right. What does the aliens' number 53 mean to us?