Biology calculations.. nm, um, mm

Something i've never been able to do on Bio exams is when they ask you to do a calculation like measuring the width of a cell, and it involves converting for example nm (nanometers?) to um or mm..

So could anyone provide a link which could explain how to do these calcultions please. Or could someone tell me how many nm are in a mm, and how many um are in a nm lol if that makes any sence.

Reply 1

Ataloss

13

stratomaster

Something i've never been able to do on Bio exams is when they ask you to do a calculation like measuring the width of a cell, and it involves converting for example nm (nanometers?) to um or mm..

So could anyone provide a link which could explain how to do these calcultions please. Or could someone tell me how many nm are in a mm, and how many um are in a nm lol if that makes any sence.

1000um = 1mm
1000nm = 1um

therefore, 1mm = 1000000nm.

HTH

Reply 2

stratomaster

OP

Thanks!

Good stuff.

Reply 3

Stranded

11

stratomaster

Something i've never been able to do on Bio exams is when they ask you to do a calculation like measuring the width of a cell, and it involves converting for example nm (nanometers?) to um or mm..

So could anyone provide a link which could explain how to do these calcultions please. Or could someone tell me how many nm are in a mm, and how many um are in a nm lol if that makes any sence.

I find it hard too sometimes :s:

Reply 4

mizfissy815

12

milli (m)- x 10^-3
micro(u)- x 10^-6
nano(n)- x 10^-9
pico(p)- x 10^-12

kilo(k)- x 10³
mega(M)- x 10⁶
giga(G)- x 10⁹

PS- this is for converting to meters...

Reply 5

Stranded

11

mizfissy815

milli (m)- x 10^-3
micro(u)- x 10^-6
nano(n)- x 10^-9
pico(p)- x 10^-12

kilo(k)- x 10³
mega(M)- x 10⁶
giga(G)- x 10⁹

PS- this is for converting to meters...

Thank you Muhiba!

Reply 6

InTeRRoGaToR

1

u muppets thats the easiest bit
its wellll easy...2 mins to learn it

Reply 7

Pandalover

what is bigger??????????????

very good

Original post by mizfissy815

milli (m)- x 10^-3
micro(u)- x 10^-6
nano(n)- x 10^-9
pico(p)- x 10^-12

kilo(k)- x 10³
mega(M)- x 10⁶
giga(G)- x 10⁹

PS- this is for converting to meters...

there is a question saying:
"convert 20nm into mm" How will I go about answering it?

Do I:
-Convert 20nm in to metres by dividing it by x10^-9
-then convert that number into x10^-3?

Reply 11

sindyscape62

10

Original post by Hiraeth.

there is a question saying:
"convert 20nm into mm" How will I go about answering it?

Do I:
-Convert 20nm in to metres by dividing it by x10^-9
-then convert that number into x10^-3?

You have the right idea - converting to meters is probably the safest way. However, to go from nm to m you should multiply by 10^-9, or divide by 10^9. Make sure you use common sense when doing these calculations, as any measurement should be less in meters than in nanometers.

Reply 12

QuentinM

17

The difference between mm, um and nm is a factor of 1,000

converting mm to um, or um to nm involves multiplying by 1,000
Converting the other way of nm to um, or um to mm, you divide by 1,000 instead

Reply 13

macpatgh-Sheldon

20

Original post by Hiraeth.

there is a question saying:
"convert 20nm into mm" How will I go about answering it?

Do I:
-Convert 20nm in to metres by dividing it by x10^-9
-then convert that number into x10^-3?

I teach these concepts to my students in a different way - instead of looking at powers (^), it is easier to think of number of zeros following the "1"

OR

for smaller units, the no of digits after the decimal point.

THIS MIGHT SEEM a BIT PROTRACTED, BUT IF YOU GO THROUGH IT SLOWLY AND TRY TO UNDERSTAND, IT WILL ALL FALL INTO PLACE! (ofc not as good as teaching it verbally)

1m = 100 cm

BUT 1 cm = 10 mm

Therefore 1m = 100 X 10 = 1000mm

1m = 1000 mm (3 zeros)

1mm = 1000 um (3 zeros)

Therefore 1m = 1000 X 1000 um = 1,000,000 um (10^6 um)

1um = 1000nm

BUT 1m = 1000 X 1000 um = 1,000,000 um

Therefore 1m = 1000 X 1,000,000 nm = 1,000,000,000 nm (10^9 nm)

SO IN ORDER:

1m = 1000 mm

1mm = 1000 um

1um = 1000 nm

AND THEREFORE:

1mm = 0.001m
1um = 0.001 mm
1 nm = 0.001 um

(m > mm > um > nm)

ALSO FROM THIS
1um = 0.001 X 0.001 m = 0.000001 m = 10^-6 m
AND
1 nm = 0.001 X 0.001 X 0.001 m = 0.000000001 m = 10^-9 m

SO FOR YOUR Q

To convert 20nm into m

1m = 1000 X 1,000,000 nm = 1,000,000,000 nm (10^9 nm)

SO 1nm = 1/1000,000,000 m = 1/10^9 m = 10^-9 m

Therefore 20 nm = 20 X 10^-9 m = 2 X 10^-8 m

Reply 14

macpatgh-Sheldon

20

Hi, @Hiraeth

Thanks for the rep - however, I did not deserve it as I did not read your Q carefully. :smile:

It should be worked out as below (nm to mm NOT nm to m)

1mm = 0.001m
1um = 0.001 mm
1 nm = 0.001 um

Therefore, 1nm = 0.001 X 0.001 mm (multiplying a nm by 0.001 gives you um, then multiplying this figure by 0.001 again gives you mm = same as dividing no of nanometres by 1000 to give value in micrometres then dividing by 1000 again to give mm)

SO 20nm = 20 X 0.001 X 0.001 = 20 X 10^-6 = 2 X 10^-5 mm

OR PUT IN DIVIDING WAY:

20/(1000 X 1000) = 2 X 10^-5 mm

M

Reply 15

Samantha9

0