By playing a game, a student must apply mathematical concepts at their level. This is how a student progresses through each game. So, by playing the games they are using and testing the concepts they need to learn.
However, to achieve the best possible results, combine playing the game with words of encouragement and with rewards along the way. Words to build their enthusiasm and confidence, rewards for good achievement.
Encourage your child/student to “not give up”. Giving up is a common problem blocking students from being their best.