Continuing to master multiplication facts with the use of multiplication guide and Strategy Ball
The days following the introduction of multiplication, you should continue to review the factors of 2 daily. This takes very little time and is well worth it. You will call on each student around the room to recite their factors of 2 (all the way to 20). This will also allow you to immediately identify those that struggle. I suggest choosing a student to work to work with those that struggle to help achieve mastery during the first couple minutes of recess each day. It is important for the students to realize that they aren't being punished for not knowing their facts.
By using Strategy Ball, this will help motivate students to want to learn. Once they realize that they can't shoot at the basket if they don't get the answer right, they will be more involved during instruction.
Teaching the factors of 5
A couple of days after you introduced the factors of 2, the students should be ready for the factors of 5. This is the easiest for the students to master since they should have been exposed to skip-counting in the earlier grades.
You will begin the lesson similar to the way you introduced the 2's. Allow the kids to review the 5's on their own and then with a partner. The final part of the lesson should be by bringing the kids back to the front and write the factors of 5 on the board.
Repeat the same method of instruction as the previous day. Choose random students to recite the factors and erase the last factor each time they get it correct.
When the students successfully erased all of the factors from the whiteboard, have them return to their seats and go around the room and have each student recite their 5's.
To conclude the lesson, engage the kids in another game of Strategy Ball that deals with factors of 5 only.