You need to write graphemes on 3 dice on each face. Consonants on two dice and vowels on the third die. Write some word for your child on the whiteboard that can be made out of rolling the dice. Then give your child a whiteboard pen and the three dice. They must roll the dice and try and match a word.
If you are working in school with activity then write the words on a piece of paper and then you can photocopy for the whole class. Children can work in pairs with 3 dice between them and a sheet of paper with the words on. They can tick or cross out the words as they roll them on the dice.