### SECOND GRADE

problem 17: Which continent has the most water?

problem 42: Our nation’s energy sources (number comparison)

problem 43: Do we use lots of energy?

problem 47: Energy sources in our state (number comparison)

### THIRD GRADE

problem 13: Who makes harmful gas?

problem 17: Which continent has the most water?

problem 30: What makes our trash?

problem 42: Our nation’s energy sources (number comparison)

problem 42: Our nation’s energy sources (converting percents to fractions)

problem 43: Do we use lots of energy?

problem 47: Energy sources in our state (number comparison)

problem 49: Solar energy in our country

### FOURTH GRADE

problem 13: Who makes harmful gas?

problem 17: Which continent has the most water?

problem 18: How is our water used?

problem 30: What makes our trash?

problem 31: How do we treat our trash in Indiana?

problem 42: Our nation’s energy sources (converting percents to fractions)

problem 42: Our nation’s energy sources (applying percents)

problem 43: Do we use lots of energy?

problem 47: Energy sources in our state (converting percentages to fractions & decimals)

problem 49: Solar energy in our country

### FIFTH GRADE

problem 17: Which continent has the most water?

problem 18: How is our water used?

problem 30: What makes our trash?

problem 31: How do we treat our trash in Indiana?

problem 42: Our nation’s energy sources (applying percents)

problem 47: Energy sources in our state (converting percentages to fractions & decimals)

problem 49: Solar energy in our country