You need to make the power of the 10s the same by adjusting the position of the decimal point as well as adjusting the power, then you can add the numbers:
9 × 10³ + 2.3 × 10⁴ = (9 × 10³ × 10/10) + 2.3 × 10⁴
= (9/10 × 10³ × 10) + 2.3 × 10⁴
= 0.9 × 10⁴ + 2.3 × 10⁴
= (0.9 + 2.3) × 10⁴
= 3.2 × 10⁴
The conversion of 9 × 10³ = 0.9 × 10⁴ should become second nature when dealing with numbers in standard form (aka scientific notation) - usually the conversion will be from a number like 0.9 × 10⁴ to put it into standard form with a digit between 1 and 9 (inclusive) before the decimal point.
9
9 x 105 = 900,000
The multiplication problem 6x10 is 60, 8x10 is 80, and 9x10 is 90.
0.9x10-1 is 0.09. In scientific notation, 9x10-2
9X10
9
9 x 105 = 900,000
B(n)=n(n+1)/2 So B(9)=9x10/2=45
9x10=90sf
The multiplication problem 6x10 is 60, 8x10 is 80, and 9x10 is 90.
9x10
90
0.9x10-1 is 0.09. In scientific notation, 9x10-2
9X10
-0.009
0.09
type in 9 x 10 then press this button (^) and press 4 and the equals sign