THIRD GRADE

problem 18: How is our water used?

problem 21: How long is our Ohio River?

problem 37: Curbside recycling in Vanderburgh

problem 46: What state produces the most coal?

problem 53: Wind race U.S. vs. China

FOURTH GRADE

problem 18: How is our water used?

problem 21: How long is our Ohio River?

problem 46: What state produces the most coal?

problem 53: Wind race U.S. vs. China

Decimal numbers

problem 48: Our electricity price–high or low?

FIFTH GRADE

problem 46: What state produces the most coal? 

problem 53: Wind race U.S. vs. China

Decimal number

problem 48: Our electricity price–high or low?