Find a 9-digit number, which you will gradually round off starting with units, then tenth, hundred etc., until you get to the last numeral, which you do not round off. The rounding alternates (up, down, up ...). After rounding off 8 times, the final number is 500000000. The original number is commensurable by 6 and 7, all the numbers from 1 to 9 are used, and after rounding four times the sum of the not rounded numerals equals 24.

Using mathematical symbols like +, -, and x in order to make the equations correct. Replace # with the above-given symbols.

9 # 8 # 7 # 6 # 5 # 4 = 91

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

If in a car race, the man who came two places in front of the last man finished one ahead of the man who came fifth, how many contestants were there?

What is the value of 1/2 of 2/3 of 3/4 of 4/5 of 5/6 of 6/7 of 7/8 of 8/9 of 9/10 of 1000?

Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

Get total of 120 by using five zeros 0,0,0,0,0 and any one mathematical operator.
Do you ?

Rectify the following equality 101 - 102 = 1 by moving just one digit.

Arrange the numbers 1, 2, 3, 4, 5, 6, 7, 8 and 9 above and below the division line in a manner that the thus formed fractions equal to 1/3.

(You can use one number only once)

What's a single-digit number with no value?