/Lab/
Ginormous numbers
We’ve been using some absolutely huge numbers.
For example:
 The sun is 5 billion years old,
 the universe is 14 billion years old,
 there are about 200 billion stars in the Milky Way
You may have heard that there are as many stars in the sky as there are grains of sand
at the beach. Let’s test that comparison and use it to get a sense of how big numbers
like million and billion are.
1. First, guess how many pounds you think a million grains of sand would weigh:
2. How many pounds do you think a billion grains of sand would weigh?
/Instructions/
1. Get the following materials:
 10 mL graduated cylinder
 spatula
2. Get the mass of your empty graduated cylinder.

mass of empty graduated cylinder:_______________
3. Using the spatula, fill your graduated cylinder with sand up to exactly the 1
milliliter (mL) mark.
4. Re-mass the graduated cylinder with sand in it.

mass of graduated cylinder + 1 mL sand: _________________
5. Find the mass of just the sand. Subtract the mass of the empty graduated
cylinder (step 2) from the mass of the graduated cylinder + sand (step 4).

mass of 1 mL sand: _____________________
6. Now, figure out a method to count how many grains of sand are in 1 mL of sand.
 You do not need to count every single grain of sand.
 You do need to come up with a method that allows you to come up with a
good estimate
 You may use whatever tools you’d like that I have available (rulers, spatulas, etc.)
 Describe your method on a separate sheet of paper.
Milky Way Image: http://commons.wikimedia.org/wiki/File:Milky_Way_2005.jpg
7. Number of sand grains in 1 mL (equal to 1 cubic centimeter):
How big is a million?
8. How many milliliters would 1 million grains of sand be?
 Take 1,000,000 ÷ the number of grains in 1 mL (step 7)

1 million grains of sand = ___________________mL
9. How many 2-Liter bottles would 1 million grains of sand fill up?
 2 Liters = 2,000 mL

Divide (step 8) by 2,000 to find how many 2-Liter bottles a million grains
of sand fill up.

1 million grains of sand = ___________________ 2-Liter bottles
10. How much would 1 million grains of sand weigh?
 Take (step 8) and multiply it by the mass of 1 mL of sand (step 5)

1 million grains of sand = ___________________ grams

Let’s change grams to pounds. Multiply your answer above by 0.0022 to
change it from grams into pounds.

1 million grains of sand = ___________________ pounds
How big is a billion?
11. How many milliliters would 1 billion grains of sand be?
 1 billion = 1,000 million

Take your answer from (step 8) and multiply it by 1,000 to find how many
milliliters 1 billion grains of sand would be.

1 billion grains of sand = ____________________ mL
12. How many 2-Liter bottles would 1 billion grains of sand fill up?
 2 Liters = 2,000 mL

Divide (step 11) by 2,000 to find how many 2-Liter bottles a billion grains
of sand fill up.

1 million grains of sand = ___________________ 2-Liter bottles
13. How much would 1 billion grains of sand weigh?
 Take (step 11) and multiply it by the mass of 1 mL of sand (step 5)

1 billion grains of sand = ___________________ grams

Let’s change grams to pounds. Multiply your answer above by 0.0022 to
change it from grams into pounds.

1 billion grains of sand = ___________________ pounds
The age of the Sun
The Sun is about 5 billion years old.
14. If you had 5 billion grains of sand, how much would it weigh?
 Take your answer from (step 13) in pounds and multiply it by 5.

5 billion grains of sand = ___________________ pounds
15. How many elephants would it take to weigh the same as 5 billion
grains of sand?
 An average elephant weighs about 10,000 pounds. Divide your answer for
(step 14) by 10,000.

5 billion grains of sand = ___________________ elephants
Stars in the Milky Way Galaxy
There are about 200 billion stars in the Milky Way.
16. If you had 200 billion grains of sand, how much would it weigh?
 Take your answer from (step 13) in pounds and multiply it by 200.

5 billion grains of sand = ___________________ pounds
17. How many elephants would it take to weigh the same as 200 billion
grains of sand?
 An average elephant weighs about 10,000 pounds. Divide your answer for
(step 16) by 10,000.

200 billion grains of sand = ___________________ elephants