Based on the profound principle: Slow and steady wins the race
1) Start with manageable steps.
2) Having mastered that step, take a small step forward.
3) Keep moving forward without taking a break... and success is sure to follow.
This app starts out with extremely simple and manageable steps
Day 1: Multiply by 1
1*1
1*2
1*3
...
2) Having mastered multiply by one, you move to day 2.
Adding 2*1 to 2*5 (not 2*1 to 2*10). Remember, simple manageable steps.
3) Day 3: 2*6 to 2*10
... you get the drill.
Practice 30 questions a day. You can set the pace for you child using the settings menu. However you can answer no more than 3 questions wrong within the time allotted to move to next day.
On completing a day successfully, you get a checkmark against that day. This helps keep track of progress and provides motivation.
An extremely simple principle indeed!
Yet more effective than any other approach you can take to acquire a new skill.