1/20 of 900 is 45.
180
25% of 900 = 25% * 900 = 0.25 * 900 = 225
22% of 900 = 22% * 900 = 0.22 * 900 = 198
80000 + 6000 + 900 + 20 + 1
225 - without using a calculator !
one hundred twenty-eight
121 is one twenty-one
Once you reach 100, counting continues by units and tens* between 100 and 200, and so forth thru 900. For numbers above 1000, a separate thousand figure is used, by units, tens, and hundreds, until 999,999 which is followed by one million. Examples: 100 = one hundred, 101 = one hundred and one, 110 = one hundred and ten, 199 = one hundred ninety-nine 200 = two hundred, 201 = two hundred and one, 299 = two hundred ninety-nine 900 = nine hundred, 901 = nine hundred and one, 999 = nine hundred ninety-nine ---------------- *Other than 10 to 20, the numbers 1-100 follow an additive form (twenty + one, twenty + two, etc.) ten eleven twelve thirteen fourteen fifteen sixteen seventeen eighteen nineteen twenty twenty one twenty two twenty three twenty four twenty five twenty six twenty seven twenty eight twenty nine thirty / thirty one ~ thirty nine forty / forty one ~ forty nine fifty / fifty one ~ fifty nine sixty / sixty one ~ sixty nine seventy / seventy one ~ seventy nine eighty / eighty one ~ eighty nine ninety / ninety one ~ ninety nine
one thousand twenty and twenty-five hundredths is written 1,020.25
Twenty one twenty fifths can be written as a fraction as 21/25.
Negative twenty nine minus negative twenty one is negative eight.
If you have twenty-seven things lined up in a row, then the last one is the twenty-seventh one.