This four digit number is a square number. 9_ _9 . What are the missing digits?

Answer 1

The missing digits are 0 and 4 (so 9409). 9409 = 97^2.

Answer 2

For a four-digit number to be a square, the root must have two digits. As the four-digit number starts with a '9', i.e. the number is in the range of 9000 - 9999, the root must be no less than 95 (since 94 squared = 8836) and no more than 99 (as 100 squared = 1000).

Since squares which end with a '9' have roots ending with '3' or '7', the only available root is 97. 97 squared is 9409, therefore the missing digits of your number are '4' and '0' in that order.

Answer 3

The only possibilities are 93^2 and 97^2 as
the only ways a square can end in 9 are
for the last digit of its square root to be 3 or 7.
But 93² = 8649,
so the only solution is 97² = 9409.
The missing digits are 4 and 0.

Answer 4

4 and 0

Answer 5

9409 = 97²

The way to solve this, by the way, is to start off at 100², which equals 10,000. Now we have to go smaller, right?
99² can't be it... it ends in a 1
98² can't be it... it ends in a 4
It can only be something ending in 7 or 3, since those squares end in 9.

So try 97², and if that didn't work, 93²...

Answer 6

9409 = 97^2

Answer 7

9409. It is the square of 97.