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February 16, 2021 at 8:41 pm #31178KenwKeymaster
Multiplication is a wonderful way to explore mathematics as well as develop mental powers of agility, memory, flexibility and creativity.
Here are seven methods covered in the course:
 Base method e.g. 87×97, Lesson 14,15 (and 31×33 using Proportionately)
2. Average e.g. 41×39, Lesson 17 (and 82×39 using Proportionately)
3. By One More e.g. 74×76, Lesson 17 (and 47×86 using Proportionately)
4. Doubling & Halving e.g. 35×46, Lesson 7
5. Eleven e.g. 43×11 (and 52×22 using Proportionately), Lesson 12
6. Addition & subtraction e.g. 34×19, Lesson 2
7. General method (vertically and crosswise) e.g. 23×31, Lesson 13
(Lesson 32 shows another multiplication method)
You can use addition and subtraction with the other methods too. For example, for 23×42 you could think of this as 22×42 + 42, so that you can use the 11 method to find 22×42 and add 42 to it.
Try these:
62 x 58 = 42 x 43 = 11 x 56 =
65 x 85 = 41 x 38 = 38 x 39 =
71 x 79 = 72 x 45 = 87 x 11 =
31 x 21 = 78 x 36 = 21 x 53 =Can you give a pair of numbers whose product cannot be found by any of the first 6 methods above?
Can you find a pair of numbers whose product can be found using all of the methods above?  Base method e.g. 87×97, Lesson 14,15 (and 31×33 using Proportionately)

February 23, 2021 at 6:50 am #31663Anupama CherukuriParticipant
Pair of the numbers whose product can be found using all the methods is 11
I am able to found the product of each pair of No. using the Base method. 65 X 85 – for this number except for the Base method and Vertical and crosswise method we can’t find the product with other methods.

February 23, 2021 at 6:51 am #31664Anupama CherukuriParticipant
Pair of the numbers whose product can be found using all the methods is 11 X 56

February 23, 2021 at 6:46 pm #31677KenwKeymaster
Thanks Anupama. Can you explain how 11 x 56 can be done by all the the 6 methods.
For 65 x 85 you can double them both and find 13×17 using By One More, put two zeros on and halve twice.

February 24, 2021 at 9:57 am #31733Anupama CherukuriParticipant
For 11 X 56
Base method – 11 + 1
14 +4 (56/4)
——————
15 4 = 154 * 4 = 616
Average = (11*4) 44 X 56 = 6 Avg = 2500 (50*50) – 6* 6 = 2464/4 = 616
By one more = (11*2) 22 X (56/2) 28 = 616
Double and Halving = (56/2 ) 28 * 11 = 308 * 2 = 616
Eleven = 56 * 11 = 5 11 6 = 616
Addition & Subtraction = 56 * 10 = 560 + 56 = 616

February 24, 2021 at 7:12 pm #31796KenwKeymaster
Thanks Anupama, this is impressive.
These special methods give us a huge range of possibilities, and inspire creativity in the classroom.

February 24, 2021 at 10:02 am #31734Anupama CherukuriParticipant
Thank you for explaining. I am still not thinking much. Need to practice on that.
These practices helping me to think about all the possibilities and making me more interested to explore. Thank you Ken.



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