9 times 10 to the 4th.
Or, 9x10(exponent=-4)
Pretty tough one. If you just remember how 10-100-1000-10,000 goes after the decimal, remember that it goes like a number line after the decimal.-10ths-100ths-1000ths-10,000ths and so on. Every time you add a zero after the decimal and before the number, it makes the number go up one in ths.