#### Sujiko

##### Place all the digits from 1 to 9 into the white boxes. Make sure the four white boxes surrounding each star add together to make the number in the star! Make sure you use each digit once only.

CLICK ON EACH BOX TO REVEAL THE ANSWERS.

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##### Select a level...

# Sujiko

How To Use This Resource

# Primary Quiz activities are designed to be displayed and used from your classroom whiteboard. All activities can be used again and again with your class. Read the instructions below to get started.

* Display this activity on your classroom whiteboard.

* Choose a level to generate a puzzle.

* Ask children to solve the puzzle by placing all the digits from 1 to 9 in each of the white boxes.

* The numbers in the four digits around each star must add together to make the value in the star.

* Click on the empty boxes to reveal each number.

* Click on <Hints and Tips> to get some clues.

* Click on a level again to generate an entirely new puzzle.

* Can you solve the Sujiko?

# HINTS AND TIPS

1. Look for scenarios where there is only one number missing from a group of four. In the example below, pupils should easily be able to work out that the missing digit (A) is 4, so that all four digits add together to make 21.

2. Where there are two numbers missing, pupils should be able to work out the sum of the two missing numbers by taking away the numbers provided from the star. So, we know that the two missing numbers B and C must add to 2 and 7 to make 16. Therefore B+C must equal 7.

3. Encourage pupils to find all possibilities. If we know that two numbers make 7, what could they be? (6+1, 5+2, 4+3). If any of these digits have already been used, we can eliminate them as options.

4. Use trial and error, especially in situations where one square has only two possibilities. If we assumed B equalled 6 and C equalled 1, what would happen elsewhere? B+D must equal 10, (5+2=7), therefore D would need to be 4. However, E cannot be 7 (in order to make 28), as this number has already been used. Therefore, B cannot be 6. Using trial and error helps us to see the implications for certain choices, allowing us to quickly eliminate (or confirm!)

certain possibilities. With practice, these strategies should enable

many pupils to solve even the toughest of Sujiko.

Good luck!

A

C

B

D

E