Maths is one subject which often young children seem to struggle with. Having a daughter who had zero confidence in her mathematical ability I know how challenging it can be to find ways of engaging a child and making them keen to learn.
Above all activities must be fun and challenging without leaving the child with any sense of failure. As a parent or teacher playing the part of someone who has no idea about maths and making obvious mistakes can put a cautious or reluctant learner at ease.
Whether using an iPad, pc, board game, whiteboard or even a simple pencil and paper variety is the key. Children like experiencing new things and can quickly become disengaged if asked to complete the same things repetitively. When acquiring apps or games it can be a case of trial and error as there are some which a child will just immediately engage with whilst others are of no interest. Free apps are an excellent way of discovering which your child finds most appealing and also which are most appropriate.