EX | Math Skills Flashcards
Calculate the percentage decrease from 10 to 1.
10 - 1 = 9
9 expressed as a % of 10 can be shown as (9/10)*100 = 90
(-)90%
Calculate the percentage decrease from 9218 to 1029.
9218 - 1029 = 8189
8189 expressed as a % of 9218 can be shown as (8189/9218)*100 = 88.8370
= (-)88.8%
Calculate the percentage increase from 10 to 11.
11 - 10 = 1
+1 expressed as a % of 10 can be shown as (1/10)*100 = 10
=10%
Calculate the percentage increase from 918 to 2948.
2948 - 918 = 2030
+2030 expressed as a % of 918 can be shown as (2030/918)*100 = 221.13
=221.1%
How many cm are in a mm?
0.1
How many cm are in a micrometer?
0.0001
How many micrometers are there in a cm?
1000
How many cm are there in a dm?
10
How many cm^3 are there in a dm^3?
1000
How many cm are there in a micrometer^3?
Remember that 1 micrometer = 0.0001 cm
Cube that - 0.0001^3 = 1.0*10^-12
= 0.000000000001 or 1x10^12
how many mm are there in a dm?
If 10 cm are in a dm then
10 micrometers in a cm so 100 micrometers in 10 cm
100 micrometers in a dm
How many micrometers are there in a dm?
If 1000 micrometers in a cm and 10 cm makes 1 dm, then
1000*10 = 10,000 micrometers
We want to find the image size:
Magnification = image size / object size
21,250 = image size / 4 micrometers
Find the image size and translate the answer to cm
Multiply 4 micrometers to cancel it out and so it becomes:
21,250 x 4 micrometers = image size (85000)
1,000 micrometers in a cm so divide by 1000
85000 / 1000 = 8.5cm
Rearrange the equation to make object size the subject:
Magnification = image size / object size
Multiply image size to get rid of it
= magnification x image size = object size
How many cm in a nanometer?
firstly if 1000 micrometers are in a cm then 0.0001 cm for micrometer
1000 nanometers in a micrometer, so divide by 1000 again
0.0001 (10^-4) / 1000 (10^3) = 0.0000001 (10^-7) cm
