Good introduction to speed mental arithmatics with concept/theory algebra backup . I had seen majority(100%) of Indian maths experts that show off how fast they do speed maths within 1 second, but 100% without theory backup ? due to topsecretconfidential ! when you try to find the rootcause yourself, it is just a simple algebra application ! nothing is TOPsecret ! There is one Indian Vedic technique , I respect them for multiply any2number by any2number , or any Nnumber by anyNnumber .But the two thousands year old technique fail when N>4numbers .Thus we have to go back to the Traditional Maths technique which we learned in Primary School, since there is no advantages comparing Indian Vedic and PrimarySchool long method .As N >6 or more ,the Vedic Method take longer time to do the multiplications. That is the reason it was lost and disappeared for more than 2000years !
超實用。
Good introduction to speed mental arithmatics with concept/theory algebra backup . I had seen majority(100%) of Indian maths experts that show off how fast they do speed maths within 1 second, but 100% without theory backup ? due to topsecretconfidential ! when you try to find the rootcause yourself, it is just a simple algebra application ! nothing is TOPsecret ! There is one Indian Vedic technique , I respect them for multiply any2number by
any2number , or any Nnumber by anyNnumber .But the two thousands year old technique fail when N>4numbers .Thus we have to go back to the Traditional Maths technique which we learned in Primary School, since there is no advantages comparing Indian Vedic and PrimarySchool long
method .As N >6 or more ,the Vedic Method take longer time to do the multiplications. That is the reason it was lost and disappeared for more than 2000years !
Bonnie老師超讚👍！
🥰🥰🥰ya~~
1:53
53*47=(50+3)(50-3)
=50^2-3^2
=2500-9
=2491
謝謝老師，非常實用!
乘法乘起來💪💪💪
和Bonnie學數學: 這還蠻實用的!
謝謝老師的分享
希望你們有收穫😆
謝謝老師慈悲
十幾乘十幾的也有類似的技巧，我小時候在報紙上看過。
15*17=(15+7)*10+5*7=255
這個只能十幾乘以十幾喔，有條件限制
(10a+b)*(10c+d) = 100ac+bd+10ad+10bc
好吧，前2:25我看懂了，後面...可以不用看了，早就忘光了...
粉餅敲黑版的聲音好震懾人心。
小知識時間：是震ㄓㄣˋ懾ㄓㄜˊ，心字旁不是手子旁。
謝謝你的分享：）
挖 學到了
好棒，希望字寫大一點點
謝謝你的建議 收到💕💕
好棒希望撞擊聲小一點
哪有這麼正的主科老師XD
(10a+b)[10a+(10-b)]可以變成(10a+5)平方-(5-b)平方啊?
不解+1，我只會直接乘開得到
100a(a+1)+b(10-b)這樣
我是真的不太想說喇...
但是...
我好像用心算比你這樣更快餒...
(啊對了老師我是706ㄉ學生~~~)
有心要教人家，就慢一點寫清楚一點，會的人何必你來教？