Suggestion 1: Have children and help them with their Maths homework. Suggestion 2: Signup with https://www.khanacademy.org/ https://www.khanacademy.org/ and wo

Suggestion 1: Have children and help them with their Maths homework. Suggestion 2: Signup with https://www.khanacademy.org/ https://www.khanacademy.org/ and work through from 1st grade until you feel that you've gone as far as you wish.