Significant Figures
Made Easy
Once Upon a Time…
Some friends decided to go to the hot
new dance club downtown.
Club Significance
Significant Members only
They got to the door all excited.
Club Significance
The bouncer was scary looking but
they were not worried at all for they
had proper identification.
As they showed their identification,
the bouncer nodded and let each one
pass until…
The bouncer gave a growl and said,
“You’re not significant FOOL! The
Significant Club had rules!”
BAD
Significant Members only
The others were inside having a grand time, not
realizing that their friends were now on their
way home totally confused as to what just
happened.
The next day at school…
• They all met back up and the story was told.
Together they all went to the library to find
out what rules the bouncer was talking about.
THE RULES!
• 1. All non zero digits are significant.
• 2. When a zero is surrounded by non zero
numbers it is significant. If more than one zero is
surrounded by nonzero numbers, the zeros
surrounded are ALL significant.
• 3. When a decimal is in a number the first
nonzero number and all numbers after it are
significant.
• 4. When a number is written in scientific
notation, all the numbers to the left of the
multiply sign are significant.
They decided to start working on the
rules one at a time, starting with the
first rule.
All non zero digits are significant.
This is why all of us who were not a zero got to
go in but the others did not!
They agreed and started to look at rule
number two.
When a zero is surrounded by non zero numbers
it is significant. If more than one zero is
surrounded by nonzero numbers, the zeros
surrounded are ALL significant.
So if we non zero numbers go in so that the zeros are in the middle, they can
get in! It is like we are sponsoring them or they are part of our crew!
But does it matter how many zeros are in the middle?
“ Nope, see it says that even if there is more than one zero surrounded, that
all the surrounded zeroes are significant.”
They all agreed and then looked at rule
number three.
When a decimal is in a number the first nonzero
number and all numbers after it are
significant.
“ I think I get this one. It’s like if you have a line and someone in the line has a
credit card and says, ‘I am paying for myself and everyone behind me.’ The
credit card is the decimal, and the guy that is using it is the first nonzero
number that appears in the lineup.”
“I guess this means if we want to have the zeros join us, they cannot
be the first one in line…it has to be a nonzero value.”
They all agreed and then looked at the
last rule
When a number is written in scientific notation,
all the numbers to the left of the multiply sign
are significant.
“ Scientific notation is when there is a multiply sign with ten to some power right?”
“Yeah, and you know that bouncer wears a different necklace when his wife is out of
town. It means that everyone in front of him gets in free to party.” They all laughed.
X
They had the rules down and now
were going to see if they could get
into the club.
• And now it’s your turn. You will be given an
identification card. Can you arrange
yourselves into a number so that all of you can
get into the club too?
By the way…whether you
got into Club Significance
or not…you’re ALL
significant to me!
The End!
Significant Members only