Hands-on math!

Washington State Math Olympiad
Hints and Solutions
2006 Grade 6 Number Sense
Problem
Hint

1) What is the missing number?
 1. In each triangle, what is the lower left number multiplied by to get the lower right number? ____.
2. The missing number is ____
(You don't need the top numbers!)

2) Right after Christmas a store put all of its winter coats on sale for 40% off. One rack had a sign saying, "Take an additional 30% off". Terri picks out a blue coat from this "30% off" rack. If the coat had an original price of $100.00, what will the coat now cost Terri? (Do not include tax.)		 1. Take 40% off the price. That leaves $____
2. Now take 30% off that _____

3) Emily Brown fills up her gas tank with premium gas at $2.25 a gallon. She pays $21.38. Miles Brown fills up their other car with regular gas at $2.05 a gallon. He pays $21.01. Who bought the most gas and how much more to the nearest 100th of a gallon?		 l. Compute the amount Emily bought as the amount she paid divided by the price per gallon = ____ gallons.
2. Compute the amount Miles bought in a similar manner = ____ gallons.
3. _____ bought the most gas
4. Subtract the lower amount from the upper and round to the nearest 100th of a gallon = ____ gallons.

Problem
Hint
4) Carol bought 2 student tickets and 3 child tickets for a play. The student tickets cost $3.00 less than an adult ticket and the child tickets cost $4.50 less than an adult ticket. An adult ticket costs $8.75. How much money did she spend on the tickets? Work this backwards:
1. If adult tickets cost $8.75 and the child ticket cost $4.50 less, then a child ticket costs _____.
2. If a student ticket costs $3.00 less than an adult, then a student ticket costs _____.
3. 2 student tickets and 3 child tickets cost _____.

5) Solve the riddle:
I am a 2-digit prime number
I am greater than 20 and less than 60
The sum of my digits is 10
Who am I?		 The prime numbers between 20 and 60 are
    ___ ___ ___ ___ ___ ___ ___ ___ ___
I am _____