Tullius, who is using MUS Gamma, learned a neat trick for multiplying by 11 last week. Any two digit number (that adds up to 9 or less) multiplied by 11 is that number...okay, I'm not going to be able to explain this. But I think I can show it.
Take 34 x 11, for example. The answer is 374 -- you split the digits 34, like this: 3___4. Then add them together (3+4) and that number goes in the middle: 374. Try it, it really works!
In this same lesson (23), double digit times double digit multiplication was introduced. Tullius does not really "get it" -- this is the first mathematical concept that he hasn't instantly understood. Anyone have any special tips or tricks for this? I'm planning to watch the video with him and do some more block building this week, instead of moving on to the next lesson.
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Not know what you have done and how you have already explained it, I will likely say things that you have done. In which case, ignore me (well,not ME, but this part!)
I found that breaking them apart into 2 separate problems to be helpful. Along with a strong and constant reminder of what place value means.
So, for 23 x 46:
remind of place values for each of the 2 numbers.
23 x 6 first. to get 138
then 23 x 4 to get 92. but remember, the 4 is in the 10's place. and when you multiply by 10's you add a zero at the end so it is actually
23 x 40 to get 920
By properties of addition and multiplication you would get the final result by adding the 2:
138 + 920 = 1058
How's that? Sorry if it stunk. I was trying to do this and help mine with his math at the same time. Email me !
melissa
Your math tip is so cool. My youngest will love that.
I am extremely impressed that your kids did so well in deciphering those runes. Some of the runes represent a two-letter sound. Here is what the message says:
Potions of any kind can be made by mixing the reagents for the spell with some water and placing it in a potion bottle.
I can email you the key for your kids if you like. And give those kids a big high five from Dickens' family.
Hi Lee! love seeing your mathmagical Monday again! Cool trick! Thanks for sharing!
Have you drawn anything latley?
Lisa
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