Cubing some digits

A self-marking multiplication exercise

This is a small task involving multiplying. It is self checking ~ which means you will know if it is correct when you have finished. It is just a quirk of maths and has no great significance. See how quickly you can achieve success. If some words ae strange to you then read on a bit ~I have provided explanations.

Start with the number 371, and take each of its digits ~ one at a time. Work out the cube of the first of the digits ~ the three. Write it down.

Note ~ to work out the cube of a number you must first of all multiply the number by itself. The answer ~ or product ~ is called the square of the number. Multiply the product by the original number and you will have a new product ~ it is called the cube. For example 5 x 5 = 25 and then the second process is 25 x 5 = 125. Or ~ to go right back to the beginning 5 x 5  5= 125. We could say ~ in words ~ that125 is the cube of 5. In mathematical symbols we write 5³. If it is difficult to see this on the screen it is a small 3 written to the right and raised to be level with the top of the number.

Now work out the cube of the second digit ~ the digit 7 ~ that is 7³. Write it down.

Now work out the cube of the third digit. Write it down.

You should have three separate numbers written down.

Work out the sum of the three numbers.

Mathematicians sometimes refer to additions in a special way ~ as summations ~ or sums. Summation means adding together. The sum of five and seven is twelve. This would normally be written with a plus sign as 5 + 7 = 12.

If you do not notice anything just a little bit surprising...try it all with another starting number...I would suggest 370. (That is much easier than it looks!)

Using the same instructions as above can you spot the odd one out of these four numbers ~

132 ~ 153 ~ 243 ~ 234

I am sure you will know when you are correct. If you cannot spot something a bit odd ~ no big deal ~ just a concidence ~ then ask an adult to help you check over your work. You may have made a slip up with your multiplication. I do not think there are any other numbers for which this 'works', so please do not spend a lot of time trying to find them. Maybe some of you could program a computer to check this.

Finally which is the odd one out here ~

183~ 235 ~ 387 ~ 407

A commentary on this task is available for BusyBusy Subscribers [126846].

Web services by ~ https://www.highview.co.uk/www

or contact ~ mail@highview.co.uk

Last updated 2020~1218...https://www.busybusy.co/page/12/68/46.htm....End of file