1. 3 Significant zeros

2. Deciding whether zeros are significant is difficult because zeros can
be used for counting OR they can be used as labels
When are zeros used for counting?
When are zeros not significant?
When are zeros used as labels?
When are zeros significant?
When they are used as labels
One example is money, such as counting “10” hundred dollar bills.
When they are used for counting
One example is money, such as the two zeros on “ hundred dollar bills.
Story Time

3. 5 $100 bills 50 $10 bills 500 $1 bills $400 to $600 $490 to $510
Suppose that you take your car to a mechanic, and he says the repair
will cost about $1 bills
Suppose that you take your car to a mechanic, and he says the repair
will cost about 50 $10 bills
Suppose that you take your car to a mechanic, and he says the repair
will cost about 5 $100 bills
Suppose that after the repair is completed the mechanic charges
you 52 $10 bills? It that acceptable?
Suppose that after the repair is completed the mechanic charges
you 51 $10 bills? It that acceptable?
Suppose that after the repair is completed the mechanic charges
you 49 $10 bills? It that acceptable?
How much money do you expect to spend?
Suppose that after the repair is completed the mechanic charges
you 499 $1 bills? It that acceptable?
Suppose that after the repair is completed the mechanic charges
you 502 $1 bills? It that acceptable?
Suppose that after the repair is completed the mechanic charges
you 501 $1 bills? It that acceptable?
Suppose that after the repair is completed the mechanic charges
you 4 $100 bills? It that acceptable?
Suppose that after the repair is completed the mechanic charges
you 7 $100 bills? It that acceptable?
Suppose that after the repair is completed the mechanic charges
you 6 $100 bills? It that acceptable?
Yes. The estimate was about 50 $10 bills, so it can be one bill more
Yes. The estimate was about 5 $100 bills, so it can be one bill less
No. The estimate was about 50 $10 bills, so it can not be two bills more
Yes. The estimate was about 5 $100 bills, so it can be one bill more
Yes. The estimate was about 500 $1 bills, so it can be one bill more
Yes. The estimate was about 500 $1 bills, so it can be one bill less
Yes. The estimate was about 50 $10 bills, so it can be one bill less
No. The estimate was about 500 $1 bills, so it can not be two bills more
No. The estimate was about 5 $100 bills, so it can not be two bills more
You expect to spend about $500 – five hundred dollars 5
$100 bills 50
$10 bills
500
$1 bills
$400 to $600
$490 to $510
$499 to $501
Both zeros are labels
So, one sig. fig.
One zero is a label
The other is for counting
So, two sig. fig.
Neither zero is a label
Both zeros are for counting
So, three sig. fig.

4. Now, how many significant figures in each number?
Here are some examples
Significant Zeros
Not significant Zeros
10001
1000.
.00015
1000
Now, how many significant figures in each number?
Are these Zeros Sig. or not Sig.
1203
Sig. 4
5460.
Sig. 4
1200
Not Sig. 2
.00546
Not Sig. 3
1200.
Sig.
5460
Not Sig. 3 4 5
.1203
Sig. 4
50406
Sig.
.1230
Sig. 4
Sig. 7
.0123
Not Sig. 3
54600.
Sig. 5

5. Now, how many significant figures in each number?
Here are some examples
Here are some examples
Significant Zeros
Not significant Zeros
10001
1000.
.00015
1000
Now, how many significant figures in each number?
12030 4
54060 4
1230 3
540.60 5
.0540 3 4 4
12.30 4
.05060 4
123.00 5
0.0056 2 5
.12030