สูตรคูณแม่ 11 ไม่ต้องท่อง

27 x 11 = ?

Split up the number.
2 ___ 7

Add up the two digits and place it in the middle
2 + 7 = 9

Result
27 x 11 = 297

---------------------------------

57 x 11 = ?

Split up the number.
5 ____ 7

Add up the two digits and place it in the middle
5 + 7 = 12

Combine the first digit to the first digit.
1+
5 2 7

Result
57 x 11 = 627


This has clearly shown that Learning Math is not about Drilling and Memorizing .
It is more of getting to know of the Right Strategies.