Hands-on math!

Washington State Math Olympiad
Hints and Solutions
2006 Grade 7 Number Sense
Problem
Solution
1) 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. A discount of 40% is a multiply of the principal (P) by _____
  2. Multiply the original price of the winter coats by the discount decimal factors = $_____
2) What is the missing number?
  1. In the first triangle the lower left number is multiplied by ___ to get the lower right number and that number is also multiplied by ___ to get the top number.

  2. You should see a similar pattern in the second triangle.

  3. Apply this pattern to the third triangle to get the lower right number = _____

3) 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 How much more money, expressed as a percentage, was spent in 2005 compared to 2004? 		For convenience, assume that the credit card users spent $100 in 2005.
  1. The they spent _____ x $100 = ______in 2004.

  2. They spent _____ more in 2005.

  3. This is _____% more.

Problem
Solution
4) The odometer on a car reads 42322 miles. In the next 200 miles how often will the odometer show a number in which exactly three of the digits are the same?
  1. In 200 miles the odometer will read _______ miles

  2. The numbers are between _______ and ________
  3. Find the numbers between these 2 values that have exactly 3 digits the same and total that number.
    I'll give you the first one = 42333





There are ____ numbers
5) A pound of hamburger is 30% beef, 30% cereal, 20% water and 20% ingredients untouched by human hands. If one pound equals 16 ounces, determine the water content in ounces of a Quarter Pounder.
  1. Multiply the percent water content by the total weight =


    _____ ounces.