Some other cheap repetition can be gained by using the Power of 2 books - you can google it. Also got some good games etc on that website. It's like a one to one coaching system - the child doesn't have to write anything down, and adult sits with child for 10mins or so each day, and you can't leave a question behind until it has been answered correctly on three consecutive occasions. Everyone starts from the beginning. So this would, certainly for number, help to flush out any weak patches from square one.
Mystery this stuff looks great, am going to investigate for my dd2 - even though my she caught up with her maths (now in yr 7) she still has these lapses where she forgets how to do something, or a concept dosnt sink in. Its odd because anything to do with shape, volume, 3D etc she finds almost easy - same with science but probability, fractions, and other number work she almost seems to have a block. Her spelling is not good but her writing content is fantastic so its like number+spelling dyslexic tendancies she has, if there is such a thing