Albert Teen YOU ARE LEARNING:  Tiny Units  # Tiny Units ### Tiny Units

Cells are super small, so it's helpful to know some units that are smaller than millimetres.

1

A typical cell is $0.01-0.1 \space mm$ 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  2

Imagine you are studying a cell that is $0.02 \space mm$ across

Those zeros and decimals could get quite confusing, so it's useful to use units that are even smaller than a millimetre. Pick all the units below that you think are smaller than a millimetre. 1

Micrometres are abbreviated $\mu m$

You can fit $1,000 \space \mu m$ inside a millimetre! 2

Now, imagine a cell that's $0.02 \space mm$ across. If you changed the unit to micrometres, would the number then be bigger or smaller than $0.02$?

A) Bigger B) Smaller  3

To convert $0.02 \space mm$ into micrometres, you need to _____________ $0.02$ by $1,000 \mu m$.

A) multiply B) divide  4

What is $0.02 \space mm$ in micrometres?  5

For every $1 \space mm$, you have $1,000 \space \mu m$

So you go from millimetres to micrometres by multiplying by $1,000 \space \mu m$ For example, $0.02 \space mm$ is the same as $20 \space \mu m$ 1

What is the abbreviation you use for nanometres?

A) $\mu m$ B) $nm$ C) $pm$  2

Nanometres are even smaller than micrometres

There are $1,000,000 \space nm$ in a millimetre! 3

So how would you change $0.02 \space mm$ into nanometres?

A) Multiply by $1,000 \space nm$ B) Multiply by $1,000,000 \space nm$  4

What would $0.02 \space mm$ be in nanometres?  5

For every $1 \space mm$, you have $1,000,000 \space nm$

So you go from millimetres to nanometres by multiplying by $1,000,000 \space nm$ For example, $0.02 \space mm$ is the same as $20,000 \space nm$ 1

What is the abbreviation you use for picometres?

A) $\mu m$ B) $nm$ C) $pm$  2

Picometres are even smaller than nanometres

There are $1,000,000,000 \space pm$ in a millimetre! 3

So what would $0.02 \space mm$ be in picometres?  4

For every $1 \space mm$, you have $1,000,000,000 \space pm$

So you go from millimetres to picometres by multiplying by $1,000,000,000 \space pm$ For example, $0.02 \space mm$ is the same as $20,000,000 \space pm$ Recap

1

Micrometres, nanometres and picometres are all smaller than a millimetre

Micrometres are abbreviated $\mu m$

Nanometres are abbreviated $nm$

Picometres are abbreviated $pm$

2

These are tiny tiny units!

There are $1,000 \space \mu m$ in a millimetre. There are $1,000,000 \space nm$ in a millimetre. There are $1,000,000,000 \space pm$ in a millimetre.

1

Now! For every $1 \space mm$, you have $1,000 \mu m$ and $1,000,000 \space nm$. How many nanometres does that mean you can fit in a micrometre?  2

So you can fit $1,000 \space nm$ in one micrometre. How would you change for example $25 \space \mu m$ into nanometres?

A) Multiply by $1,000 \space nm$ B) Multiply by $1,000,000 \space nm$  3

What would $25 \space \mu m$ be in nanometres, then?  4

For every $1 \mu m$, you have $1,000 \space nm$

So you go from micrometres to nanometres by multiplying by $1,000 \space nm$ For example, $25 \space \mu m$ is the same as $25,000 \space nm$ 1

How would you convert from nanometres to picometres?

A) Multiply by $1,000 \space pm$ B) Multiply by $1,000,000 \space pm$ C) Multiply by $1,000,000,000 \space pm$  2

How would you convert from micrometres to picometres?

A) Multiply by $1,000 \space pm$ B) Multiply by $1,000,000 \space pm$ C) Multiply by $1,000,000,000 \space pm$  3

Now! How would you convert from nanometres to millimetres?

A) Multiply by $1,000,000 \space nm$ B) Divide by $1,000,000 \space mm$  4

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). What would $0.035 \space mm$ be in micrometres? What would $75 \space \mu m$ be in picometres? What would $47 \space pm$ be in nanometres? 1

Summary! Cells are only about $0.01-0.1 \space mm$ across

So it's useful to have smaller units so you don't have to deal with all those zeros and decimals. 2

Micrometres, nanometres and picometres

There are $1,000 \space \mu m$ in a millimetre. There are $1,000,000 \space nm$ in a millimetre. There are $1,000,000,000 \space pm$ in a millimetre. 3

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. 