299x78巧算怎么做 486-299的算式巧算怎么做
299\u4e58\u4ee581\u7684\u5de7\u7b97\u600e\u4e48\u505a
\u56fe
486-299
=486-300+1
=186+1
=187
299×78
=(300-1)×78
=300×78-78
=23400-78
=23 322
原式等于
78×(300-1)
=78×300-78×1
=23400-78
=23322
回答完毕~
299x78
=(300-1)x78
=300x78-78
=22400-78
=22322
谢谢,请采纳
绛旓細99脳78+33脳66 =99脳78+99脳22 =99脳(78+22)=99脳100 =9900
绛旓細鍘熷紡=99*78+99*22 =99*锛78+22锛=99*100 =9900
绛旓細宸х畻:78x99 78x99 锛78x(100-1)=78x100-78 =7800-78 =7722
绛旓細宸х畻杩囩▼瑙f瀽301脳78 瑙i鎬濊矾:鍥涘垯杩愮畻瑙勫垯(鎸夐『搴忚绠,鍏堢畻涔橀櫎鍚庣畻鍔犲噺,鏈夋嫭鍙峰厛绠楁嫭鍙,鏈変箻鏂瑰厛绠椾箻鏂)鍗宠劚寮忚繍绠(閫掔瓑寮忚绠)闇鍦ㄨ鍘熷垯鍓嶆彁涓嬭繘琛 瑙i杩囩▼:301脳78 =300脳78+78 =23400+78 =23478
绛旓細99*78+33*66 =99*78+99*22 =99*锛78+22锛=99*100 =9900
绛旓細38x26鍗26X13 51x7鎬庝箞宸х畻? 38x26+26x13+51x7=锛38+13锛墄26+51x7=51x26+51x7=51x(26+7)=51x33=1683 178x78涓78x78宸х畻鎬庝箞鍋? 178x78=13884 78x78=6084 13884-6084=7800 宸х畻:8888x7-1111x44-2222 8888X7-1111X44-2222 =1111X8X7-1111X44-1111X2 =1111X56-...
绛旓細99脳78+66脳33 =99脳78+22脳锛3脳33锛=99脳78+22脳99 =99脳锛78+22锛=99脳100 =9900
绛旓細25x16x25x84=25x4x(25x4)x84=100x100x84=840000 78+22x7=78+(20+2)x7=78+20x7+2x7=78+140+14=232 39x102=39x(100+2)=39x100+39x2=3900+78=3978 104x25=(100+4)x25=100x25+4x25=2500+100=2600 {25x13}x4==25x13x4=25x4X13=100X13=1300 ...
绛旓細宸х畻杩囩▼鏂规硶濡備笅 瑙:锛815-789锛壝78 =26脳78 =26脳锛80-2锛=26脳80-2脳26 =2080-52 =2028
绛旓細8*2=16鏄湯灏句袱浣 7*锛7+1锛=56鏄墠涓や綅 鎵浠ヤ负5616