15. Each ? below represents a factor between 1 and 9. Draw lines to match each fact on the left with a pattern for its products on the right.

? XO

O in the ones place

? X1

O or 5 in the ones place

? x 2

0,2,4,6, or 8 in the ones place

? X 5

The other factor in the ones place

? X9

1 less than the unknown factor in the tens place