• 1 x 9 + 2 = 11
• 12 x 9 + 3 = 111
• 123 x 9 + 4 = 1111

And so on... go on....try it for yourself!

How far can you go?

Try this with your friends! Pick any 2 digit number e.g 49

• Multiply by 3
• Multiply by 7
• Multiply by 13
• Multiply by 37

The final answer will be the original number written out three times!

(so 49 x 3 x 7 x 13 x 37 = 494949)

Try 11 or 32 or 57 - they all work!

• 1 x 8 + 1 = 9
• 12 x 8 + 2 = 98
• 123 x 8 + 3 = 987
• 1234 x 8 + 4 = ????
• 12345 x 8 + 5 = ?????
• 123456 x 8 + 6 = ??????
• 1234567 x 8 + 7 = ???????
• 12354678 x 8 + 8 = ????????
• 123546789 x 8 + 9 = ?????????

Can you work all these out?

Using a calculator work out how many seconds you've been alive. Don't forget leap years, the day you were born and all the seconds working this out!

If you are 10 years old you should have a figure of around 300 million seconds.

One billion seconds is about 32 Years.

If you add up the numbers 1-100 (1+2+3+4+5...) the total is 5050.

No piece of paper can be folded in half more than 7 times. It doesn't matter how big it is - try it and see!

111,111,111 x 111,111,111

= 12,345,678,987,654,321

The signs to these sums have been left out. can you guess what they are?

35 64=99

60 15=4

75 60=15

999 333=666

22 41=63

19 3=57

To remember your 9 x table try this:

Write the numbers

0 1 2 3 4 5 6 7 8 9

Then directly underneath backwards

9 8 7 6 5 4 3 2 1 0

Can you see it? You can read vertically all the answers to 10 x 9!

Here's a cool mathematical trick:

Write down a 3 digit number whose digits are decreasing. Then reverse the digits to create a new number, and subtract this number from the original number. With the resulting number, add it to the reverse of itself. The number you get is 1089!

For example, if you start with 532 (three digits, reversing order), then the reverse is 235. Subtract 532-235 to get 297. Now add 297 and its reverse 792, and you'll get 1089!

1 274 953 680

..is a cool number. You can divide it by any number between 1 and 16 without leaving a remainder! Try it with a calculator.

..it also contains all the numbers 0 - 9.

Please get an adult to help!

How many times would you need to wind a piece of string around your head before it was the same measurement as your height?

.. three times - try it and see.