To

To

**add (or subtract)**numbers in scientific notation, you need to convert them to numbers with a common multiplier. Then, add (or subtract) in the usual way, and apply the multiplier to the result.__Examples__2.5*10^-3 + 4*10-6 = 2500*10^-6 + 4*10^-6 = (2500+4)*10^-6 = 2504*10^-6 = 2.504*10^-3 4*10^2 - 3*10^3 = 0.4*10^3 - 3*10^3 = (0.4 - 3)*10^3 = -2.6*10^3To

**multiply (or divide)**numbers in scientific notation, you multiply or divide in the usual way, making use of the rules for exponents.__Examples__(2.5*10^-3)(4*10-6) = 2.5*4*10^-3*10^-6 = 10.0*10^((-3)+(-6)) (when multiplying, the exponents add) = 10.0*10^-9 = 1.00*10^-8 (4*10^2)/(-3*10^3) = (-4/3)*10^2/10^3 = (-4/3)*10^(2 - 3) (when dividing, the denominator exponent is subtracted from the numerator exponent) = (-4/3)*10^-1 ≈ -1.333*10^-1