How many white rods are equal to the red rod?
Can you show me?
Are any other rods the same length as the red?
How do you know they are equal?
What does equal even mean?
Why is the green not equal?
Which rods are equal to the green rod?
Can you check?
Can you find more rods which are equal to the rod?
Without even knowing it, children are completing models of mathematical equations. You can ask questions to encourage exploration but once they have got started the chances are they will continue the exploration in their own way.