Optional Activities
Microbe Size Comparison
Big Ideas:

• Microbes are very, very small.
• Some are smaller than a speck of dust or the width of a hair.
• You need special tools (like microscopes) to see them.
• Microbes can still do important jobs, even though they’re tiny!

Wondering Together

Ask: 
- “Do you think you could see a microbe with your eyes?”
- “What do you think is bigger: a hair, a grain of sand, or a microbe?”

Introduce:

• Microbe = a living thing that is so small, you need a microscope to see it.
• Microbes include bacteria, archaea, and even viruses (which aren't truly alive on their own).

Explore: Visual Size Comparison


Show a picture or scale diagram that includes:

• A human hair (~70 micrometers wide)
• A grain of sand (~500 micrometers)
• A bacterium (~2 micrometers)
• A virus (~0.1 micrometers)

Ask Level 1:

• “Which one is the biggest?”
• “Which one is the smallest?”
• “Would you need your eyes or a tool to see the microbe?”

Ask Level 2:

• “How many bacteria do you think could fit across a hair?” (Estimate: about 35!)
• “Why do you think scientists need microscopes?”

Videos
https://youtu.be/4S0EjrRdMHc 
 
A Billion Tiny Things
Big Ideas:

• A billion is a really big number
• Microbes are really small
• Even the tiniest things can have a big impact

Goals:

• What is a billion?
• How small are microbes?
• How can something tiny be found in such big numbers?

How Much Is a Million? by David M. Schwartz
Focus on the section about how long it takes to count to a million or billion
Pause and let kids guess/estimate before revealing
Key line: “If you wanted to count from one to a billion, it would take you about 95 years!”

Tiny Creatures: The World of Microbes by Nicola Davies
Talk about where microbes are found
Highlight the idea that there can be billions of microbes in a spoonful of soil or drop of water

Activity Ideas
1. Build a Billion (Big Numbers Exploration)
Materials: beads, LEGO, paper dots, beans, blocks—anything countable

• Create piles:
• 10 dots
• 100 dots
• 1,000 dots
• 1 million? Let them guess what that would look like (use a visual or say “it would fill a bathtub!”)
• Ask: “How much space do you think a billion would take up?”

2. Microbe Scale Challenge

• Show size comparisons:
• Human hair ≈ 100 microns
• Bacterium ≈ 2 microns
• Virus ≈ 0.1 microns
• Ask: “How many bacteria would fit across a pencil tip?”
• Answer: About 50,000
• Then: “If we lined up a billion bacteria, how far would they stretch?”
• Answer: Over 1 mile!

Discussion Questions

• What surprised you about how big a billion is?
• Why do we need special tools to see tiny creatures?
• Can something too small to see still be powerful? Why?
• How does knowing about microbes help us?

 Activity: A Billion Takes a While...Level 2 Focus: Scale, multiplication, time, and critical thinking

How Long Would It Take to Do Something a Billion Times?
Start with this question:
"What would happen if you tried to do something a billion times?"
Have learner(s) estimate or guess first. Then walk through a few fun scenarios together:
Clapping Your Hands

• 1 clap per second = 60 claps per minute
• 60 × 60 = 3,600 claps/hour
• 3,600 × 24 = 86,400/day
• 1,000,000,000 ÷ 86,400 ≈ 11,574 days = over 31 years, non-stop

“Would your hands even survive?!”

Writing Your Name

• 5 seconds to write your name
• 12 names per minute
• 720 names/hour
• 8,640 names/day (writing all day)
• 1,000,000,000 ÷ 8,640 ≈ 115,740 days = 317 years

“What would you do with a billion signatures?”
Spending $1000 a Day

• 1,000,000,000 ÷ 1,000 = 1,000,000 days
• 1,000,000 ÷ 365 = over 2,739 years

“You’d need to spend $1,000 a day for almost 3,000 years to run out of a billion dollars!”

Discussion Questions:

• Why do billionaires still have money after buying so much stuff?
• Is it fair for someone to have that much?
• What would you do with a billion dollars?

Optional Mini-Challenge:Have learner come up with their own:

• "What if I jumped a billion times?"
• "What if I blinked a billion times?"
• "What if I earned $1 every time I did a chore—how long until I got to a billion?"

Let them calculate it out with your support, great for math integration!