Did you know that the Ancient Egyptians were really good at Math?
Here, I'll show you one very clever trick they used for multiplication.
There's also a video from youtube at the end, so you can watch that if you feel the instructions here are not good enough.
(pixabay.com)
Instructions
Take two numbers to be multiplied - I will use 17 and 25 as those are the numbers used in the accompanying video.
So, we have,
17 x 25
Step 1
With the first number (17) we need a list of numbers, starting at the number one, which doubles each time:
1
2
4
8
16
32
etc.
Next, we find the numbers in that list which, when added together will equal the number, i.e. 17.
1 + 16 = 17, so we have
(1)
2
4
8
(16)
32
Step 2
With the second number for our multiplication (25), we make a list which doubles each time, but this time using 25 as the starting number:
25
50
100
200
400
800
etc.
We now put the two lists side by side:
(1).....................25
2.......................50
4.......................100
8.......................200
(16)...................400
32......................800
Step 3
Finally, we see which numbers in the second list correspond with the ones which we 'found' from the first list in Step 1 - that is the numbers in the second list which correspond to the numbers 1 and 16.
25 corresponds to 1, and
400 corresponds to 16
We get the answer by adding these two numbers, 25 and 400 = 425
Therefore,
17 x 25 = 425
Here's the link to the youtube video:
Thanks for looking at my post and..
... be happy!
