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Carol K
10-05-2009, 10:23 AM
It's more of a vent. On friday we were learning the third of the geometric shapes, the "Rectangular block". (page 128/9 pf Early bird Textbook A). Well today we went on a treasure hunt for rectangular blocks around the house. DS would find them and go "this is a rectangular block!" After the lesson, I decided to scheme ahead for tomorrow's lesson and from page 131, the rectangular block becomes a cuboid! :surprise: I had wondered why they were not calling it a cuboid to begin with and even asked DH what he called that solid. It's got to be confusing to the child to tell them, "well actually it is called a cuboid and not a rectangular block. Why didn't they just give it one name? just venting a little frustration. Lesson learnt is to scheme way ahead!

Jeni
10-05-2009, 10:33 AM
At least they didn't tell you to call it a rectangular parallelepiped (http://en.wikipedia.org/wiki/Parallelepiped) :lol:

There are many names and disputed definitions to go with the shapes and solids in geometry. There is absolutely no reason a 5 year old needs to know that a rectangular block can be called a cuboid. Mention it in passing if you want and move on. If he still wants to call it a rectangular block, that's fine. If he thinks cuboid is an interesting word and wants to use that, that's fine too. I wouldn't stress about it. If they can see that cyan, aquamarine, cerulean, robin's egg and navy blue are all shades of blue I think he can handle more than one name for a rectangular solid. ;)<input id="gwProxy" type="hidden"><!--Session data--><input onclick="jsCall();" id="jsProxy" type="hidden">

Carol K
10-05-2009, 01:25 PM
Good points Jen. I guess I was expecting some consistency.

Carol K
10-06-2009, 07:06 PM
I was still curious so I asked Singapore Math about it and Jenny from SM sent a response. I knew there had to be another reason for the use of the two names. I went to school in a foreign country so I have had to relearn a lot of things including different names. But, my curiosity is now satisfied. For anyone that's curious I thought I'd share her response.

Her response:

Keep rectangular block.

In Singapore, a cube is a cube, and a cuboid is a rectangular prism. Cuboid is what rectangular prism was called in 3rd edition and I think US edition of Primary Mathematics. In Standard edition, it is changes to US term of rectangular prism. If you want to continue with standards edition, keep calling it a box or rectangular block. Early in Standards edition, it is called box shape. Rectangular prism is later. By all means keep rectangular block if he already know the name.

By the way, he should eventually learn that in everyday language, things get called by different names sometimes. He ought to be able to associate rectangular block with box shape if that comes up in Primary Mathematics. And later with cuboid, if you end up using US edition. It is when they get to more formal geometry that more formal names need to be used. If you want to teach the formal name now, that is fine, and rectangular block is closer to rectangular prism than box or cuboid is.

Holly S
10-07-2009, 01:52 PM
Thanks for posting the response. We're also using EM Level A, but not quite that far yet.