1. eNRICHing Number & Algebra Bromley February 2015

2. Dicey operations Find a partner and a dice.
Each of you draw an addition grid.
Take turns to throw the dice and decide which of your cells to fill.
Throw the dice nine times each until all the cells are full.
Whoever has the sum closest to 1000 wins.

3. Cryptarithms Can you find a solution to all of the cryptarithms?
Do any of them have more than one solution?

4. Two and Two
How many solutions can you find to this word-arithmetic challenge?
Can you find other word sums that work?

5. Forwards Add Backwards
The number 726 can be formed by adding a 3-digit number with its reversal.
Can you find other ways of making 726 in this way?
Which numbers between 700 and 800 can be formed from a number plus its reversal?

6. Mind Reader

7. Got It

8. The Factors and Multiples Game
A game for two players.
You will need a 100 square grid.
Take it in turns to cross out numbers, always choosing a number that is a factor or multiple of the previous number that has just been crossed out.
The first person who is unable to cross out a number loses.
Each number can only be crossed out once. 8

9. The Factors and Multiples Challenge
This time, try to find the longest sequence of numbers that can be crossed out.
Again, choose a number that is a factor or multiple of the previous number that has just been crossed out.
Each number can only appear once in a sequence.

10. Which mixture has the stronger tasting lemonade?
Mixing Lemonade
Which mixture has the stronger tasting lemonade?
How do you know?

11. What’s the best order for laying down the cards?
A Chance to Win?
What’s the best order for laying down the cards?

12. Temperature The freezing point of water is 0°C and 32°F.
The boiling point of water is 100°C and 212°F.
Is there a temperature at which the Celsius and Fahrenheit readings are the same?

13. What’s it worth?
Each symbol has a numerical value. The total for the symbols is written at the end of each row and column.
Can you find the missing total that should go where the question mark has been put?

18. Summing consecutive numbers
Give me a whole number…

19. Pair products Choose four consecutive whole numbers.
Multiply the first and last numbers together.
Multiply the middle pair together.
What do you notice?

20. What’s Possible?
Give me a whole number…

21. What’s Possible?
Can you find a way to write each number from 1 to 30 as the difference of two squares?
Can you write any of them in more than one way?
If I give you a number, can you tell me all the possible ways to write it as the difference of two squares?

22. Number collection Algebra collection http://nrich.maths.org/8702