# Structure 3.5

Number Sentences

Make three stories that show how you would work out three unknowns – one using addition, one using subtraction, and one using multiplication. Show you understand that subtraction is the opposite of addition,  addition is the opposite of subtraction, and division is the opposite of multiplication. An example of all three is below.

Order of Operations

Venn and Carroll Diagrams

Design an experiment where you are measuring how something changes over time.
Some ideas are…

Does the number of people going to the bathroom change during the day?
What times of day do people use their netbook the most?
How do your reflexes change over the day?
How does your memory change during the day?
Do people use drink taps at certain times during the day?
How long does it take to forget something?
When is the warmest time of the day?
Do students call out more often at certain times of the day?
How does the length of a shadow change during the day?
Do people yawn more at certain times of the day?

When you’ve figured out how you will do your experiment, record your results and record on your blog what you found out (written or an audio file). Include a table with the time in one column and the thing you are measuring in the other.