Hands-on math!

Washington State Math Olympiad
Hints and Solutions
2008 Grade 8 Number Sense
Problem
1) Insert an additional set of parenthesis to make the following number sentence true.
8 - 6 - 3 x (4 - 10) ÷ 2 + 1 = 18
2) What is the smallest whole number exponent, n, for which 1 - (1⁄3) n is greater than 1 - (0.2)3 ?

3) A builder orders 2 by 4 lumber for a project and always tags on an extra 5% rounded up just in case. If the total number of 2 by 4s is 625 how many of those are extra 2 by 4s that the builder may not need?

Problem
4) A sequence is created as follows:

What is the distance between the 9th and 10th term of the sequence when plotted on a number line?
Express your answer as a fraction.

5) A government program has a cost overrun of 0.3% on a total budget of 2 billion dollars. What will the overrun cost the tax payers? Express your answer in scientific notation.