I like ratios. All the introductory skills are performed using whole numbers. Therefore, I think this is a topic/concept that should be taught in primary schools. I have found that, when properly introduced, children adapt quite well to this kind of thinking.
I start by calling it sharing. Every child is familar with the concept of sharing … one for me, one for you, two for you … and can predict how many items each person will have after a given number of cycles. They do this when dealing cards, for example.
Many students have watched concrete being made. When I explain how a labourer will have a pile of blue metal (aggregate), a pile of sand, and a supply of cement powder, and how they load the mixer, most of them readily understand the process and can calculate what a labourer would need to do for a double load. Most can even suggest two methods/sequences for loading the mixer.
In my opinion, it is vital that students learn to set their work out clearly in columns and that, except for the most elementary problems, the first line should consist of column headings. You will see more of this when I begin adding material here.
Rates compare measurements of ‘like’ quantities, for example two distances or two times or two money amounts. They are normally written side-by-side separated by colons (:). All will be revealed as I add material to this page!
Brilliant!!! This helps so much!!! So much easier than anything else I have found. This is now simple.
Thanks again for showing the simple way of doing this. I look forward to the next video!! Absolutely brilliant.
Once again, excellent! I’ve watched many others, that have not helped nearly as much as these. Thanks for making it so easy to understand. When things get complicated, it is easy to make a mistake, but your method of writing down the structure helps to prevent mistakes.
Thanks a million!!! I’ve watched many videos and read tutorials, but still could not get two in a row correct on Khan Academy. Your explanation was so clear and simple that it finally made sense to me and now I can get all of the problems correct!!! Thank you very much.
It all makes total sense now! Thanks very much for all the derivative videos!!! Very helpful.
MemorizeAndLearn (on four different CCM YouTube videos about Differentiation)
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