for a problem like this, we have to think logically
we know that 6 * some number in the thousands must equal 25 thousand something. Let's say we put 5 in that first spot, 6 * 5,000 is already 30,000 so that's wrong. If we go one lower, 6 * 4,000 is 24,000 and so now we can include the 287 knowing it will fit.
so 6 * 4287 = 25,722.
all we do now is fill in the blanks to match our answer.