### Consecutive Numbers

An investigation involving adding and subtracting sets of consecutive numbers. Lots to find out, lots to explore.

### I'm Eight

Find a great variety of ways of asking questions which make 8.

### Calendar Capers

Choose any three by three square of dates on a calendar page. Circle any number on the top row, put a line through the other numbers that are in the same row and column as your circled number. Repeat this for a number of your choice from the second row. You should now have just one number left on the bottom row, circle it. Find the total for the three numbers circled. Compare this total with the number in the centre of the square. What do you find? Can you explain why this happens?

# Reverse Subtraction

##### Stage: 3 Short Challenge Level:

c is 3.

There are five possible pairs of values for a and b (assuming a cannot be zero).
They are (1,5), (2,6), (3,7), (4,8) and (5,9).

Note that the pair (3,7) means a = c.
Perhaps you would prefer not to include this but it is not strictly ruled out by the problem.

All give c as 3. Why?

This problem is taken from the UKMT Mathematical Challenges.
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