$\begingroup$ If we were to ask how many 1000 digit numbers with no zeroes were multiples of nine just think of all of the wasted page space your answer would use. . Meanwhile, using the elegant approach, you say "oh, just pick the first $999$ digits normally and then the choice for the last digit is forced so the answer is $9^{999}$" taking no space at all. $ How to Convert Thousands to Hundreds. There are 10 hundreds in a thousand ie. 1 thousand is equal to 10 hundreds. So to convert thousands to hundreds just multiply thousands value with 10. Example : to convert 1 thousand to hundred. 1 thousands equals 1 x 10 hundreds i.e 10 hundreds. 1) Convert to molarity: 2) Convert mol/L to grams of sodium ion per 1000 g of solution: mol/L times 23.00 g/mol x 2 = 0.001104 g/L. 3) Convert to ppm by multiplying numerator and denominator by 1000: 0.001104 g/1000 g of solution times 1000/1000 = 1.104 g / 1,000,000 g of solution. The solution for sulfate is left to the reader. Many of you will find the 1-100 Roman numeral chart covers most of the numbers in which they are interested, and if you are looking to understand Roman numerals in outlines, clock faces or other everyday instances, the 1-100 chart is perfect. You can pick a chart of Roman numerals 1-1000 if your counting demands are somewhat larger. 17a & 17b. Transcribed Image Text: 17. a. How many integers are there from 1000 through 9999? b. How many odd integers are there from 1000 through 9999? c. How many integers from 1000 through 9999 have dis- tinct digits? d. I'm trying to count all 9's in numbers from 1 to n, including repeating digits such as in 99. My code (python 3) works and returns the corrects answer for most cases except for very large numbers (like 20 digit numbers). 1000 or one thousand is the natural number following 999 and preceding 1001. In most English-speaking countries, it can be written with or without a comma or sometimes a period separating the thousands digit: 1,000. A group of one thousand things is sometimes known, from Ancient Greek, as a chiliad. Total number of times = (20).(9) + (11).(9) + 21 = 180 + 99 + 21 =300 Therefore when we list numbers from 1 to 1000 the digit 5 is written 300 times. Option (c) is correct. Note: Don’t forget to count the digit 5 twice in numbers like 55, and also do not forget to count the digit 5 in hundredth’s place in the numbers from 500 to 599. 0jyGa.