In school, my daughter was struggling in Multiplication. The trick to get her back on track was to get her to practice regularly. It was a tug-of-war game of will and perseverance between us parents and my daughter. I thought of a simple app by which she could work on towards a target (say 4th table). She need to pass 80% in 2 minutes on 4's table and she would be off the hook for the day. No need of looking over the shoulder, just set a target and let her go. We raised up the bar in couple of days/weeks. She came out as school's top three in basic math.
Now you could do the same for your kid. Ask your kid to do a base level. Let them attain 80% or 100% as you choose on a particular table. Let them try again and again until they achieve it. When they achieve, give a reward at this time before moving to next level.
Your kid will be a winner.