8.76e7 mW = 8.76e4 W (move decimal point 3 places to right)
8.76e4 W = 8.76e1 kW
8.76e1 kW = 8.76e-2 MW
8.76e-2 MW = 8.76e-5 GW
or you can just divide by 1e12
8.76e7 mW / ( 1e12 mW/GW) = 8.76e-5 GW
But this defeats the entire reason for using metric prefixes. You usually don't mix exponential notation with metric prefixes, it gets confusing.
The correct expression would be either 8.76e4 W or 87.6 kW
PS, I hope you are not confusing mW and MW, two totally different things.
If there is one thing you need to learn, it's metric
prefixes. You will use them in a variety of ways the rest
of your life, no matter what you do.
SI (metric) prefixes:
da (deca) = x10 (rarely used)
h (hecto) = x100 (rarely used)
k (kilo) = x1000 = e3
M (Mega) = x1000000 = e6
G (Giga) = x1000000000 = e9
T (Tera) = x1000000000000 = e12
P (Peta) = e15
E (Exa) = e18
Z (Zetta) = e21
Y (Yotta) = e24
d (deci) = /10 = e-1 (rarely used)
c (cent) = /100 = e-2 (rarely used except for cm)
m (milli) = /1000 = e-3
µ (micro) = /1000000 = e-6
n (nano) = /1000000000 = e-9
p (pico) = /1000000000000 = e-12
f (femto) = e-15
a (atto) = e-18
z (zepto) = e-21
y (yocto) = e-24
8.76e4 W = 8.76e1 kW
8.76e1 kW = 8.76e-2 MW
8.76e-2 MW = 8.76e-5 GW
or you can just divide by 1e12
8.76e7 mW / ( 1e12 mW/GW) = 8.76e-5 GW
But this defeats the entire reason for using metric prefixes. You usually don't mix exponential notation with metric prefixes, it gets confusing.
The correct expression would be either 8.76e4 W or 87.6 kW
PS, I hope you are not confusing mW and MW, two totally different things.
If there is one thing you need to learn, it's metric
prefixes. You will use them in a variety of ways the rest
of your life, no matter what you do.
SI (metric) prefixes:
da (deca) = x10 (rarely used)
h (hecto) = x100 (rarely used)
k (kilo) = x1000 = e3
M (Mega) = x1000000 = e6
G (Giga) = x1000000000 = e9
T (Tera) = x1000000000000 = e12
P (Peta) = e15
E (Exa) = e18
Z (Zetta) = e21
Y (Yotta) = e24
d (deci) = /10 = e-1 (rarely used)
c (cent) = /100 = e-2 (rarely used except for cm)
m (milli) = /1000 = e-3
µ (micro) = /1000000 = e-6
n (nano) = /1000000000 = e-9
p (pico) = /1000000000000 = e-12
f (femto) = e-15
a (atto) = e-18
z (zepto) = e-21
y (yocto) = e-24