How
Many?
Conversions
Add/Subtract
Multiply/Divide
Mix It Up!
10
10
10
10
10
20
20
20
20
20
30
30
30
30
30
40
40
40
40
40
50
50
50
50
50
Question 1 - 10
• How many significant Digits are in this
number:
1422
Answer 1 – 10
• 4!
• All numbers present are between 1 and 9.
Question 1 - 20
• How many significant digits are in the
following number?
200
Answer 1 – 20
• There is only 1!
• The zeros don’t count because the number
doesn’t have a decimal place in it!
Question 1 - 30
• How many significant ZEROs are in the
following number?
0.0030050
Answer 1 – 30
• 3!
• The captures zeros and the trailing zero are
the only ones that are significant!
Question 1 - 40
• What is the length of the following green bar?
Answer 1 – 40
• 1.25!
• The 1 and the 2 are in concrete, the 5 can be a
different number that is reasonable.
Question 1 - 50
• How many zeros in the following number are
NOT significant?
.0005050090
Answer 1 – 50
• 3!
• Only the zeros in the beginning of the number
do not count!
Question 2 - 10
• Convert the following:
254.3 grams to
Kilograms
Answer 2 – 10
• .2543 Kg
• The number will get smaller because the unit
gets bigger!
Question 2 - 20
• How many milliliters are in the following
number?
0.0367 Liters
Answer 2 – 20
• 36.7 mL
• The number gets bigger because the unit gets
smaller!
Question 2 - 30
• Which weighs more?
4.25 grams of Au or
425 mg of Au
Answer 2 – 30
• 4.25 grams does!
• Convert milligrams to grams and you get .425
mg! That is less than 4.25 grams!
Question 2 - 40
• What is the metric prefix that correspond to
the following quantity?
-2
10
Answer 2 – 40
• Centi!
Question 2 - 50
• How many mL are in the following number?
87 DL
Answer 2 – 50
• There are 870,000 mL!
• KHD*dcm
Question 3 - 10
• What is the answer to the following addition
problem?
212.2 + 26.7 +
402.09
Answer 3 – 10
• Addition, so look for least # of decimal places!
• 641.0
Question 3 - 20
• What is the answer to the following addition
problem?
2
2.01x10
+
3
3.014x10
Answer 3 – 20
• 3215
• You have to take the numbers out of scientific
notation to look at decimal places!
Question 3 - 30
• What is the answer to the following problem?
52.331 + 26.01
– 0.9981
Answer 3 – 30
• 77.34
• Watch number of decimal places here! Add
and subtract carry least number of decimal
places to the answer.
Question 3 - 40
• How many digits after the decimal point
should be reported when the following
calculation is performed?
199.0354 + 43.09
+ 121.2
Answer 3 – 40
• There should only be 1 decimal place in this
answer!
Question 3 - 50
• How many digits after the decimal place
should be reported when the following
calculation is performed?
10,434 – 9.3344
Answer 3 – 50
• There will not be any decimal places in this
number! 
Question 4 - 10
• What is the answer to the following division
problem?
12.011 /
23
6.022x10
Answer 4 – 10
• 1.995x10-23
• We need to look at number of significant
digits in the numbers of the problem—least
number determines answers sig figs!
Question 4 - 20
• What is the answer to the following problem?
(4.031)(0.082068)(373.1)
/.995
Answer 4 – 20
• 124
• Remember least # of sig figs will be reported
in the answer!
Question 4 - 30
• The answer to the following question should
be written with how many significant digits?
2
2.3733x10 /
343
Answer 4 – 30
• 3!
Question 4 - 40
• When the following calculation is performed,
the answer should be reported with how
many significant digits?
.0043*.0821*298
Answer 4 – 40
• 2!
• Remember least goes! 
Question 4 - 50
• What is the answer to the following problem?
-4
2
(6.1982x10 )
Answer 4 – 50
• 3.8418x10-7
• Or 3.8000x10 -7
Question 5 - 10
• What is the answer to the following problem?
(2.0944+.0003233*12.22)
/7.001
Answer 5 – 10
• .2997
• Remember your order of operations!
• Please Excuse My Dear Aunt Sally!
Question 5 - 20
• What is the answer to the following problem?
2
3
[(1.42x10 )+(1.021x10 )]/
-1
3.1x10
Answer 5 – 20
• 3.8x103
Question 5 - 30
• Consider the following numbers 23.68 and
4.12.
• The sum of these numbers has how any
significant digits?
• The product of these numbers has how many
significant digits?
Answer 5 – 30
• Sum has 4
• Product has 3
Question 5 - 40
• You pour the water from these beakers into a
separate container. What is the volume with
the correct number of significant digits.
Answer 5 – 40
• Your answer should range from 81 to 82 mL
without any decimals!
Question 5 - 50
• Report the volume of the water in each beaker
with the proper # of significant digits.
Answer 5 – 50
• I has 26.4(ish) mL
• II has 28(ish) mL
• III has 26.42(ish) mL
• The –ish comes from your interpretation.
Remember the first digits are known and the
last digit is an educated guess (is it uncertain).