1998 CEMC Gauss (Grade 7) Problems/Problem 6

Problem

In the multiplication question, the sum of the digits in the four boxes is:

[Multiply using long multiplication. Find the sum of the four numbers in the thousands place column.]

Solution

Multiplying, we find that the numbers in the thousands place column are 1, 9, 1, and 2 respectively. Adding yields a sum of 12, so the answer is

-edited by coolmath34

If anyone knows the LaTeX to show long multiplication, any help would be appreciated.

-edited by De-math-wiz

Solution

While doing the long multiplication the numbers in the thousand place are 1, 9, and 2 respectively. When added the sum is 13, so the answer is (A) 13

879x492 = 432,468

    879
  x 492
  1,758
 79,110

+351,600

=432,468

Therefore add 1+9+1+2 = 13, so (A) 13 is correct answer.