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3. Why do people believe that six degrees of separation is a real phenomenon?
4. When a clearance sale offers 75% off the original price of an item you want and the store is giving a
20% off of any purchase during Black Friday, what are your actual savings for that one item?
H
ardest Problem
How hard
can
it be? Can you still use what you’ve learned?
Find what you consider the hardest number to make sense of. List all the reasons why it is so difficult.
How do you address these issues so that new numbers will make more sense?
T
roubleshooting
Find the error and correct it!
Identify the error and provide a correction:
Grover had been working as a guide at the natural history museum for 25 long but happy years. One
day, a young girl stood in front of him and, pointing to a huge skeleton of a T-Rex on display, asked,
“How old is that dinosaur?” Grover hunkered down and said, “Why he’s precisely 65 million and
25 years old!” The little girl’s eyes grew wide. “How do you know so exactly how old he is?” she
rightly asked. Grover responded, “On my very first day working here, I asked one of the scientists
how old Rex was. He told me that carbon dating showed that the skeleton was 65 million years old,
plus or minus a million years. That was almost exactly 25 years ago!” The little girl’s eyes narrowed
with suspicion. She knew she was being had, but wasn’t sure just how.
M
aking it Matter
Solving problems in your life
In life we come across situations where, if we can’t make sense of a number, we don’t know what
choice to make. A very common situation is two boxes of cereal. The larger box is currently selling for
less than the smaller box because of a sale. Why would anyone want choose to pay more for less? But
many people do. Often stores provide a pricing rate (dollars per ounce, for example). Armed with that
information, you can compare which gives the greater value which can easily be defined as “the fewest
dollars per ounce” for this situation. People who can’t make sense of what a rate of “$/ounce” means end
up ultimately basing their decisions not on value but on packaging. Manufacturers know this; there’s a
reason that packaging is bright, colorful, and attractive.
Find four additional examples where a number is confusing for people, thus leading them to ignore it
or make poor decisions. Identify the number, determine what the number means, and determine how to
clearly explain the sense of that number to a general audience. Here are some ideas to get you started;
use them or find contexts of your own.
●
Nutrition labels on food: How do you determine quantity based upon a realistic serving size?
●
APR: What does it really mean, especially with respect to a car loan?
●
Credit card charges: How are they really calculated and what are they based on?
●
National debt vs gross national product: You hear the numbers in the news, but what do they
really have to do with the economy?
1.5 Number Sense