# World of Tan 30 - Logical Thinking

This activity, the last in the World of Tan series, follows on from World of Tan 29 - The Telephone.

Thinking logically is what Little Ming and Little Fung try to do all the time! This is when you solve a problem step by step, checking that each step makes sense. You try different ways of solving the problem, and if one choice doesn't work then you try the next one instead. If you get stuck, think about what you've already tried - what do you still have left to try? Write down all the things
that you know already - can you use any of those as a stepping stone to finding a solution?

There are lots of games and activities you can enjoy which will make use of logical thinking. Have a look at other pages on this website for more ideas.

Try to logically construct both of these silhouettes. Does anything surprise you about the similarities and differences in the solutions?

Extra activities:

- Think about a time when you were trying to solve a problem and you got stuck. How did you get 'un-stuck'? What or who helped you? How?
- Have a go at the activities in these lists, using sentences like 'I think... because...' to explain your logic to a friend.

### Why do this problem?

This problem is an engaging context in which pupils can consolidate their knowledge of the properties of squares, triangles and parallelograms. By attempting this activity, children will be putting into practise their visualising skills, making guesses about where the different shapes might go before trying out their ideas. When combining the shapes to make the tangram, pupils will use their understanding of translations, reflections and rotations to decide how to transform each shape. There are also links between tangrams and fractions, and children can be encouraged to work out what fraction of the whole square is represented by each smaller shape.### Possible approach

Read this story with the whole class and look at the tangram as a group. Ask pupils to suggest where a shape might go. What transformation would be needed to move the shape into that position?When pupils are solving the tangram, they would benefit from working in pairs with a tablet or a printed copy of the shapes to cut out and move around. Working together will lead to rich discussions about the possible options for where each shape can go. When the children have solved the tangram, they can have a go at the extra activities.

At the end of the lesson, bring all of the pupils together and model the solution on the whiteboard. How does each shape need to be transformed? What fraction of the whole picture is each shape?

### Key questions

What could you put with this piece to make a square?Are all of the pieces different?

What's the smallest square you can make?

What has to go in that space? How do you know?