Problem Solving with Our Special Visitors

Today we are holding a special event called

This is an afternoon for all the students to show a special person some of the things they have been using their netbook for in class.

We have prepared a problem solving activity for our students to solve with their special person.

We have a toolkit of problem solving strategies that we often use in our maths lessons. Perhaps one of these strategies will help solve today’s problem?

Today’s Problem: Sealed Solution

This problem is from the NRICH website.

A set of ten cards, each showing one of the digits from 0 to 9, is divided up between five envelopes so that there are two cards in each envelope. The sum of the two numbers inside it is written on each envelope:


What numbers could be inside the “8” envelope?

Note: there is more than one solution.

Write your solution in a comment. You might like to say what problem solving strategy you used to work this out.