Answer:
0
Explanation:
Given the difference:

In front-end rounding, we consider the number with the largest place value.
In -36.673, the number with the largest place value is 3.
The digit after 3 us 6, so we round up as follows:

Likewise, In 39.999, the number with the largest place value is 3.
The digit after 3 us 9, so we round up as follows:

Therefore:

The diffrence is 0 using front-end rounding.