YOU ARE LEARNING:
Tiny Units
Tiny Units
Cells are super small, so it's helpful to know some units that are smaller than millimetres.
A typical cell is 0.01−0.1 mm across. How many cells does that mean you can fit next to each other within a millimetre?
A) 1 cells B) 1-10 cells C) 10-100 cells
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/Dd3cVRYBRyOhdGXVIIuS.png)
Imagine you are studying a cell that is 0.02 mm across
Those zeros and decimals could get quite confusing, so it's useful to use units that are even smaller than a millimetre.
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/Dd3cVRYBRyOhdGXVIIuS.png)
Pick all the units below that you think are smaller than a millimetre.
You can select multiple answers
Micrometres are abbreviated μm
You can fit 1,000 μm inside a millimetre!
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/rolBJ6OQLODZkhiICWgf.png)
Now, imagine a cell that's 0.02 mm across. If you changed the unit to micrometres, would the number then be bigger or smaller than 0.02?
A) Bigger B) Smaller
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/rolBJ6OQLODZkhiICWgf.png)
To convert 0.02 mm into micrometres, you need to _____________ 0.02 by 1,000μm.
A) multiply B) divide
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/rolBJ6OQLODZkhiICWgf.png)
What is 0.02 mm in micrometres?
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/rolBJ6OQLODZkhiICWgf.png)
For every 1 mm, you have 1,000 μm
So you go from millimetres to micrometres by multiplying by 1,000 μm For example, 0.02 mm is the same as 20 μm
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/rolBJ6OQLODZkhiICWgf.png)
What is the abbreviation you use for nanometres?
A) μm B) nm C) pm
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/hroXU5WLSnK84ECeHBy5.png)
Nanometres are even smaller than micrometres
There are 1,000,000 nm in a millimetre!
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/hroXU5WLSnK84ECeHBy5.png)
So how would you change 0.02 mm into nanometres?
A) Multiply by 1,000 nm B) Multiply by 1,000,000 nm
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/hroXU5WLSnK84ECeHBy5.png)
What would 0.02 mm be in nanometres?
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/hroXU5WLSnK84ECeHBy5.png)
For every 1 mm, you have 1,000,000 nm
So you go from millimetres to nanometres by multiplying by 1,000,000 nm For example, 0.02 mm is the same as 20,000 nm
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/hroXU5WLSnK84ECeHBy5.png)
What is the abbreviation you use for picometres?
A) μm B) nm C) pm
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/pAlxTDcSQQOLzk8eFEL5.png)
Picometres are even smaller than nanometres
There are 1,000,000,000 pm in a millimetre!
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/pAlxTDcSQQOLzk8eFEL5.png)
So what would 0.02 mm be in picometres?
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/pAlxTDcSQQOLzk8eFEL5.png)
For every 1 mm, you have 1,000,000,000 pm
So you go from millimetres to picometres by multiplying by 1,000,000,000 pm For example, 0.02 mm is the same as 20,000,000 pm
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/pAlxTDcSQQOLzk8eFEL5.png)
Recap
Micrometres, nanometres and picometres are all smaller than a millimetre
Micrometres are abbreviated μm
Nanometres are abbreviated nm
Picometres are abbreviated pm
These are tiny tiny units!
There are 1,000 μm in a millimetre. There are 1,000,000 nm in a millimetre. There are 1,000,000,000 pm in a millimetre.
Now! For every 1 mm, you have 1,000μm and 1,000,000 nm. How many nanometres does that mean you can fit in a micrometre?
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/hroXU5WLSnK84ECeHBy5.png)
So you can fit 1,000 nm in one micrometre. How would you change for example 25 μm into nanometres?
A) Multiply by 1,000 nm B) Multiply by 1,000,000 nm
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/PZFu3o1KRrqGhjaW0R4k.png)
What would 25 μm be in nanometres, then?
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/PZFu3o1KRrqGhjaW0R4k.png)
For every 1μm, you have 1,000 nm
So you go from micrometres to nanometres by multiplying by 1,000 nm For example, 25 μm is the same as 25,000 nm
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/PZFu3o1KRrqGhjaW0R4k.png)
How would you convert from nanometres to picometres?
A) Multiply by 1,000 pm B) Multiply by 1,000,000 pm C) Multiply by 1,000,000,000 pm
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/l11mJw4BTVCdRtBKlSGc.png)
How would you convert from micrometres to picometres?
A) Multiply by 1,000 pm B) Multiply by 1,000,000 pm C) Multiply by 1,000,000,000 pm
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/l11mJw4BTVCdRtBKlSGc.png)
Now! How would you convert from nanometres to millimetres?
A) Multiply by 1,000,000 nm B) Divide by 1,000,000 mm
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/l11mJw4BTVCdRtBKlSGc.png)
Make sure you know if you are going to a smaller unit or to a bigger one!
If you go from bigger to smaller, you should multiply (for example from millimetres to micrometres).
If you go from smaller to bigger, you should divid****e (for example from picometres to nanometres).
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/wfVLlkgkR8O5kdVcCGQW.png)
What would 0.035 mm be in micrometres?
What would 75 μm be in picometres?
What would 47 pm be in nanometres?
Summary! Cells are only about 0.01−0.1 mm across
So it's useful to have smaller units so you don't have to deal with all those zeros and decimals.
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/l11mJw4BTVCdRtBKlSGc.png)
Micrometres, nanometres and picometres
There are 1,000 μm in a millimetre. There are 1,000,000 nm in a millimetre. There are 1,000,000,000 pm in a millimetre.
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/l11mJw4BTVCdRtBKlSGc.png)
Be careful when you convert from one unit to another!
If you go from a bigger unit to a smaller unit, you should multiply. If you go from a smaller unit to a bigger unit, you should divide.
![](https://cdn.hejalbert.se/teen/blocks-images/en_GB/wfVLlkgkR8O5kdVcCGQW.png)