Going from scientific notation to standard notation...
A positive exponent means "make the number bigger by that many decimal places."
7.83 x 10^6 = 7830000 (the decimal point moved 6 places to the right)
9 x 10^5 = 900000 (the decimal point moved 5 places to the right)
A negative exponent means "make the number smaller by that many decimal places."
5.67 x 10^-7 = 0.000000567 (the decimal point moved 7 places to the left)
1.36 x 10^-4 = 0.000136 (the decimal point moved 4 places to the left)