Hands-on math!

Washington State Math Olympiad
Hints and Solutions
2014 Grade 6 Number Sense


Problem
1) The digits 2, 3, 4, 5, 6, 7, and 9 can be placed into the boxes to make the equation true. Each one is used exactly once. Notice the multiplier is a decimal. What is the product?
2) Ben wants to make a lot of crepes. He has 3 cups of milk left and 1 and 1/2 cup of flour. He has plenty of eggs and everything else he needs. The recipe calls for 3/4 cups milk and 3/8 cup flour and yields 6 crepes. What is the maximum number of crepes he can make with the ingredients he has?

3) In a class of 30 students, exactly 5/6 have cell phones, exactly 2/5 have pocket calculators, and exactly 3/10 have both. How many of the students have neither?

Problem
4) The sum of two positive integers is 30 and their product is 216. Find the positive distance between the two numbers.

5) Emmalee wrote 6 different numbers, one on each side of 3 cards, and laid the cards on a table as shown below. The sums of the two numbers on each of the three cards are equal. The three numbers on the hidden sides are prime numbers. What are the hidden numbers behind each card? List them in order: what number goes with 44, what number goes with 59 and what number goes with 38?