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VR type 28
Posted: Thu Jul 17, 2008 9:01 pm
by Kusum
can anyone explain and solve these two sums for me?
6(15)11 9(16)15 4( ? )11
20(13)6 25(15)5 23(? )7
Thanks.
Posted: Thu Jul 17, 2008 9:24 pm
by patricia
Dear Kusum
6(15)11 9(16)15 4( ? )11
11 – 6 = 5 + 10
15 – 9 = 6 + 10
11 – 4 = 7 + 10 = 17
20(13)6 25(15)5 23(? )7
20 + 6 = 26 divided by 2 =13
25 + 5 = 30 divided by 2 = 15
23 + 7 = 30 divided by 2 = 15
Patricia
Posted: Thu Jul 17, 2008 9:27 pm
by chad
Ohhhh! Patricia....
I had just worked them out...about to post.... you beat me to it.... real shame as I don't often 'get' these (but at least I came up with the same answer as you)
Posted: Thu Jul 17, 2008 10:06 pm
by Kusum
Thanks a ton...my son & I feel real silly now.
Posted: Thu Jul 17, 2008 10:18 pm
by chad
Don't feel silly..... Patricia is very experienced.... and I went thru it with my son nearly 3 years ago.... it still took me about 10 mins to work it out.
Practice really does help - as you start to apply different stratagies without thinking.
Posted: Thu Jul 17, 2008 11:15 pm
by patricia
chad wrote:
Practice really does help - as you start to apply different stratagies without thinking.
Chad, You sound like me!
Kusum, Chad is so right, my students can now
'see' the rule almost immediately. Practice does make perfect.
Patricia
type 28
Posted: Mon Jul 21, 2008 3:26 pm
by Amanda123
Hi Guys - I am new to this , but you mention stratergies when dealing with these equations... what exactly do you mean ?
Posted: Mon Jul 21, 2008 6:09 pm
by Mike
Hi Amanda123
This question type has a range of variances that get progressively more difficult.
To work them our quickly and accurately students need to have good mental arithmetic skills. Particularly useful are timestables and the ability to multiply and divide outside the standard 10 x 10 tables.
The easier questions are single functions
+
-
x
divide
Then there are combinations. Some combinations are trickier than others such as multiply, then add a constant.
Children should be taught to identify basic questions first then be confident to attempt more difficult questions.
Generally, if the number in the middle is smaller than the outside numbers you will need to subtract, divide, half, subtract a constant at some point. If the number is higher you will need to add, multiply, double, add a constant
A good range of question variances can be found in a free methods & techniques course in the free download section of the site.
Regards
Mike