What strategy can I use to solve 6x7 and 3x9?

You could use multiplication charts and arrays. (there are more)

Well, there are many strategies you can use to solve those problems. You can either use:

1. A Multiplication table

2. A number line

Or

3. Break it down

Example: 8 * 12

What I can do to "break it down" is I can substitute '12' as '10 + 2' and then simply multiply.

(8 * 10) + (8 * 2) = 80 + 16

80 + 16 = 96

So, in this case, 8 * 12 = 96; does this make sense?