The 3 digit number that is FUN is; 678
We are told that MATH is 3 times the word "FUN".
We are also told that each letter is assigned a unique number and that no leading digit can be zero and that the digits must be consecutive.
Now, product of 789 by 3 gives;2367.
Each letter should have a unique letter and so that is not the correct sequence.
Let us try the product of 678 by;
678 * 3 = 2034
This fulfils the condition of the question because each letter has a unique digit, the lead digit is not zero and the numbers are consecutive numbers in increasing order.
Thus, the 3-digit number that is FUN is 678.
Read more about combination of numbers at; https://brainly.com/question/12468032