Hands-on math!

Washington State Math Olympiad
Hints and Solutions
2009 Grade 5 Algebra
Problem

1) Jim likes to text message. The cell phone family plan his parents have allows for 250 text messages per month for $5.00 as part of the plan and additional text messages cost 15 cents per message both incoming and outgoing. What is the total number of messages Jim can send and receive for less than $10.00 if no one else in his family texts?

2) Hannah has some pencils in her pencil case. She loans 1/6 of the pencils to Tommy and then 3 pencils to Marc. On her way home from school Hannah loses 50% of her remaining pencils through a hole in her bag. When she gets home she realizes that she only has 6 pencils left. How many pencils did Hannah start the day with?

Problem

3) Pictured is a sequence of growing chairs. The first chair is made of 6 squares. How many more squares are in the 8th chair in the sequence than in the first?

4) A boy lives on the same road as his school and the road is straight. He bikes to school. When he reaches halfway he notices he has dropped his math book. He bikes back 400 yards to pick it up. He is now 1300 yards from school. How far is his house from school?

5) Mr. Jones takes three taxi cab rides with the same cab driver. The table shows how many miles he traveled and what the taxi fare was. Plot the points on the grid provided and use the information to decide what the base fare without tip is for a trip that is 6 miles long.