Primary school maths covers an immense area, taking seven years to learn. Therefore software with only three levels - easy, medium and hard, is of doubtful value. Look for software with several levels and a variety of activities, often set in an adventure format, to hold interest and increase learning. Generally speaking, avoid maths software in an arcade game format or with time limits that can't be switch off. There is a shortage of good maths software for secondary school students.
Most students find text books more interesting.
But I am still unclear whether what they offer is educational. They help kids with computer skills, and the experience they gain in manipulating colour and layout fits well into the recommendations of the Australian guidelines on Science and technolgy. So painting with a computer can't entirely replace colouring by hand. Using a word processor can benefit kids from four up. Children can type on a PC long before they have the fine motor control to write the actual letter by hand.