Why do this problem?
challenges pupils in a novel situation, which may seem simple at first. It combines spatial awareness and number awareness.
Introduce dice to the children by asking what they already know about them. You could then talk about what numbers are visible when they are on a table. Next, make the train shape using differently coloured dice and talk about what numbers are on top.
When they are happy with that, introduce the rule about the 'funnel number' and the 'carriages numbers'. They can then talk about the numbers that face each other. When they are comfortable with the rules they can start setting about finding examples that work.
You may wish to stop at a suitable moment to bring the children back together for a short time (a mini plenary). You could ask children to share ways of working which may help all learners in the group progress.
What numbers have you got that equal each other?
Tell me how you are finding more solutions.