explain how you know that in ? x 6.273 = 6.273. THe ? will be 1.

because 1 is the multiplicative identity.

1*n = n

for any value of n. Since the number is the same on both sides, the ? is 1.

Or, you can do it the hard way:

n * 6.273 = 6.273
Now divide everywhere by 6.273

n = 6.273/6.273 = 1