Strategies for the 6X facts build on other facts students have explored. Basically, they use the distributive property to break it into two easier facts. These are the two most common approaches.
If students know the 3X fact, then the 6X fact is double that. Students need to be shown this visually. The half and double anchor chart has a sample visual explanation using arrays.
Using 5 Strategy Cards
These cards show students the x10 facts and visually why the x5 fact is half of that.