A bat and a ball cost $1.10. The bat cost $1 more than the ball. How much does the ball cost? Adapted from Prof Kehman about the system 1 and system 2 thinking. System 1 thinking is effortless,associative while system 2 is effortful and not so straightforward. So not worry too much. Most princeton kids answered wrongly. So make a guess yah. Will be answered in the next post.
Currently I am reading this book entitled Think Maths Like a Genius. So the really useful thing that i have learnt in it is this. A 2 by 2 multiplication ofany 2 digit number multiplied by 11. This is how it works. For example 43×11=473, i got this in a second, the condition is just that u add the 4 and 3 together then u put in in the middle to get 473. So now u will think, wat if it is 57×11? Since 5 and 7 add together is 12, u cannot possibly put 5127 right?Cos that would be wrong. So the tenth place in this case the 1 of the 12 will added to 5, then the answer would be 627.
Lets try a few:
1.44×11
2.53×11
3.88×11
Ans: 484,583,968
Piece of Cake yah?
How i wish my teachers taught me that?
