Let´s say I have
(5.74*10^14)(3.53*10^9)
and for that matter, that same equation, but:
(5.74*10^14) + (3.53*10^9)
(5.74*10^14)  (3.53*10^9)
Suprisingly I know what to do when dividing.
(5.74*10^14)(3.53*10^9)
and for that matter, that same equation, but:
(5.74*10^14) + (3.53*10^9)
(5.74*10^14)  (3.53*10^9)
Suprisingly I know what to do when dividing.

(5.74*10^14)(3.53*10^9)
To multiply, multiply the coefficients and add the exponents
So 5.74 * 3.53 * 10^(14 + 9) You get to do the final math
You may need to adjust the coefficient and exponent in the final result to match the standard form of one number to the left of the decimal in the coefficient.
for example, 16.5 * 10^12 = 1.65 * 10^13
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To add or subtract numbers in sci notation you need to make the exponents the same, then add the coefficients
(5.74*10^14) + (3.53*10^9) isn't a really convenient example so lets change the problema bit
(5.74*10^14) + (3.53*10^13)
(5.74*10^14) + (0.353*10^14) See what we did with that second term? We increased the exponent by 1 (multiplied by 10) and then moved the decimal in the coefficient to the left one place (divided by ten)
(5.74*10^14) + (0.353*10^14) = (7.74 + 0.353) * 10^14 You do the final math.
You know dividing... just like multiplication in reverse  divide the coefficients and subtract the exponents.
Go forth and calculate!
To multiply, multiply the coefficients and add the exponents
So 5.74 * 3.53 * 10^(14 + 9) You get to do the final math
You may need to adjust the coefficient and exponent in the final result to match the standard form of one number to the left of the decimal in the coefficient.
for example, 16.5 * 10^12 = 1.65 * 10^13
======
To add or subtract numbers in sci notation you need to make the exponents the same, then add the coefficients
(5.74*10^14) + (3.53*10^9) isn't a really convenient example so lets change the problema bit
(5.74*10^14) + (3.53*10^13)
(5.74*10^14) + (0.353*10^14) See what we did with that second term? We increased the exponent by 1 (multiplied by 10) and then moved the decimal in the coefficient to the left one place (divided by ten)
(5.74*10^14) + (0.353*10^14) = (7.74 + 0.353) * 10^14 You do the final math.
You know dividing... just like multiplication in reverse  divide the coefficients and subtract the exponents.
Go forth and calculate!

When dividing numbers in exp format :
dived the mantissas and subtract the exponents.
dived the mantissas and subtract the exponents.

do stuff in brackets first and then the other bits.