Day Four Try these. 1


Yuri thought of a number. He multiplied it by 7, then added 12 and ended up with 110. What number did he start with?


Top tip: Begin at 110 and undo each step to find the number that Yuri started with.


Answer: 2 is a number. If you multiply you will get 72 . What is the value of


by 9, you get ?


Marks: . If you add 13 to , /2


Answer: 3 . When I took 34 from


is a number. I found one-quarter of it and got , I was left with 23


. I divided


Marks: . What is the value of


/2


by 3 and got ?


Answer: Super Sleuth challenge it with a partner.


Marks: Today’s Marks:


/2 /6


Puzzle power Create your own puzzle that requires the strategy of working backwards to solve it. Share


Nim is a strategy game that has been played by maths students all over the world. It is around 1,000 years old! You can use unifix cubes to play this game in pairs.


1. Place 16 cubes on your desk between you and your partner. 2. Each player takes turns picking up 1, 2, 3 or 4 cubes at a time.


3. The player who is left with the last cube loses.


Play this game a few times with your partner. Devise a strategy that will ensure you win every time. Try out your plan a few times. Did it work?


Total Marks: /30 I will use this strategy in future when | I can work backwards to solve a maths puzzle. Yes No 83


Week 19 | Strategy: Working Backwards


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