The table you drew under the question is exactly the right way to start.
-- Make a second column, next to the 6 and 7. This column will be the actual number of each thing.
-- You know that there are 42 marbles, so write '42' in the box next to the 6, on the 'Marbles' line. Now you need to figure out what to write in the 'Stones' line, next to the 7.
-- Look at the 'Marbles' line. There's a 6 and then a 42. Ask yourself: " Self ! What does the 6 have to be multiplied with to get 42 ?"
-- Whatever the answer is, drop down to the 'Stones' line, and multiply the 7 by the same number. The product is the total number of stones, and it goes in the box. . . . (The mystery number is 7. There are 49 stones.)
