计算24乘5可以先算4乘5等于20在算2乘5等于10最后算几加几等于几 2乘3加3乘4加4乘5加5乘6—直加到100乘101的简便计...
1\u4e582\u52a0\u4e0a2\u4e583\u52a0\u4e0a3\u4e584\u52a0\u4e0a4\u4e585\u52a05\u4e586......18\u4e5819\u52a019\u4e5820 \u600e\u4e48\u7b97\uff1f1x2+2x3+3x4+\u2026\u2026+19x20
=1x\uff081+1\uff09+2x\uff082+1\uff09+\u2026\u2026+19x\uff0819+1\uff09
=\uff081+2²+3²+\u2026\u2026+19²\uff09+\uff081+2+3+\u2026\u2026+19\uff09
\u524d\u534a\u90e8\u5206\u6709\u516c\u5f0f\uff1a1²+2²+..+n²=n(n+1)(2n+1)/6
\u540e\u534a\u90e8\u5206\u5c31\u662f\u7b49\u5dee\u6570\u5217\u6c42\u548c
\u76f4\u63a5\u5e26\u5165\u4e24\u4e2a\u516c\u5f0f\u5c31\u884c\u4e86
\u53e6\u5916\u6700\u597d\u5bf9\u524d\u4e00\u4e2a\u516c\u5f0f\u8fdb\u884c\u8bc1\u660e\uff0c\u65b9\u6cd5\u662f\u5f52\u7eb3\u6cd5\u3002
\u89e3\uff1a\u4ee4S=2\u00d73+3\u00d74+4\u00d75+5\u00d76+6\u00d77+....+100\u00d7101
3S=2\u00d73\u00d73+3\u00d74\u00d73+4\u00d75\u00d73+5\u00d76\u00d73+6\u00d77\u00d73+....+100\u00d7101\u00d73
=2\u00d73\u00d7(4-1)+3\u00d74\u00d7(5-2)+4\u00d75\u00d7(6-3)+5\u00d76\u00d7(7-4)+6\u00d77\u00d7(8-5)+...
...+100\u00d7101\u00d7(102-99)
=-1\u00d72\u00d73+2\u00d73\u00d74-2\u00d73\u00d74+3\u00d74\u00d75-3\u00d74\u00d75+4\u00d75\u00d76-4\u00d75\u00d76+6\u00d77\u00d78....
....-99\u00d7100\u00d7101+100\u00d7101\u00d7102
=-1\u00d72\u00d73+100\u00d7101\u00d7102
=1030194
S=343398
以先算4乘5等于20
在算20乘5等于100
最后算100加20等于120
绛旓細3銆4銆5銆7绠24鐐圭殑绠楀紡鏈夛細(5+3)脳(7-4)=24銆(7-3)脳5+4=24銆1銆(5+3)脳(7-4)鐨勮绠楄繃绋嬩负锛氬厛绠楁嫭鍙烽噷鐨5+3=8锛7-4=3锛屽啀绠椾箻娉8脳3=24銆2銆(7-3)脳5+4鐨勮绠楄繃绋嬩负锛氬厛绠楁嫭鍙烽噷鐨7-3=4锛屽啀绠椾箻娉4脳5=20锛屾渶鍚庣畻鍔犳硶20+4=24銆24鐐规湁涓瀹氱殑瑙ｉ鎶宸э紝鐢变簬璁＄畻...
绛旓細杩炰箻鐨勫紡瀛愶紝鍚勪釜鍥犲紡涔嬮棿鏄彲浠ヨ皟鎹綅缃殑銆傝繖閲屾湁涓涓皬鐭ヨ瘑鐐癸紝閭ｅ氨鏄25脳4鏄釜鏁存暟100銆傜劧鍚24脳5=120 銆 閭ｄ箞鐙瓙灏卞彲浠ュ彉鎴250脳4脳24脳5=120000銆傚氨姣旇緝瀹规槗绠椾簡锛屽彛绠楀氨鑳藉嚭鏉ョ瓟妗堛備綘鎸夌収浠栫粰瀹氱殑椤哄簭涓椤逛竴椤圭殑绠楋紝閭ｅ氨寰堥毦绠楀嚭鏉ラ渶瑕佸垪寮忓瓙銆
绛旓細(5 1)脳5=30--6脳4=24--3024 1.4.鍗佷綅鐩稿悓,涓綅涓嶄簰琛,鍗矨=C,B D鈮10,S=A脳(A 1)脳10 A脳B鏂规硶:鍏堝ご鍔犱竴鍐嶄箻澶翠袱,寰楁暟涓哄墠绉,灏句箻灏,鐨勬暟涓哄悗绉,涔樻暟鐩稿姞,鐪嬫瘮鍗佸ぇ鍑犳垨灏忓嚑,澶у嚑灏卞姞鍑犱釜涔樻暟鐨勫ご涔樺崄,鍙嶄箣浜︾劧渚:67脳64(6 1)脳6=42 7脳4=28 7 4=11 11-10=1 4228 60=4288...
绛旓細杩欎釜棰樻垜鐭ラ亾锛屽簲璇ユ槸灏忓浜屽勾绾х殑鐭ヨ瘑銆傝繖涓睘浜庢槗閿欓鍝︼紝璁╂垜鏉ョ粰浣犺瑙ｄ竴涓嬪惂锛1銆鍏堣绠鍑虹瓟妗 4脳5=20 2銆佽浣滐細4涔5绛変簬20銆3銆佸彛璇锛氬洓浜斿緱浜屽崄鎴栬呮槸鍥涗簲浜屽崄銆傝繖閲岄渶瑕佹敞鎰忎互涓嬪嚑鐐癸細1銆佹暟瀛楀拰姹夊瓧鐩哥粨鍚堛4鍜5杩樻槸鍐欐暟瀛楋紝浣嗘槸x闇瑕佸彉鎴愭眽瀛椻滀箻鈥濓紝浣嗘槸涓嶈兘鍐欌涔樹互鈥濄2銆佸皬鏁板湪鍓...
绛旓細鑴卞紡璁＄畻40脳5 瑙ｉ鎬濊矾:鍥涘垯杩愮畻瑙勫垯(鎸夐『搴忚绠,鍏堢畻涔闄ゅ悗绠楀姞鍑,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▼:40脳5 =4脳5脳10 =20脳10 =200
绛旓細5銆4*((5+7)-6)=24 6銆4*(5+(7-6))=24 7銆4*(7+5-6)=24 24鐐规父鎴忚鍒欙細姣忎釜鏁板瓧鍙敤涓娆,浣嗗彲浠ヨ皟鎹㈤『搴,鍙厑璁稿姞銆佸噺銆涔銆侀櫎绛夊洓鍒欒繍绠,鍙互浣跨敤鎷彿鏀瑰彉杩愮畻椤哄簭銆浜屽崄鍥鐐规槸涓绉嶇泭鏅烘父鎴忥紝瀹冭兘鍦ㄦ父鎴忎腑閿荤偧浜轰滑鐨勫績绠楋紝瀹冨線寰瑕佹眰浜轰滑灏嗗洓涓垨鑰呬簲涓暟瀛楄繘琛屽姞鍑忎箻闄ゅ洓鍒欐贩鍚...
绛旓細456瑕绛変簬24闇瑕佺敤鍙栨ā杩愮畻绗︹%鈥濇潵璁＄畻銆傛湰棰樻槸涓涓墿灞曟濈淮鐨勯棶棰橈紝棰樼洰瑕佹眰鍙兘鍐欒繍绠楃鍙凤紝涓嶈兘鏀瑰彉鏁板瓧椤哄簭锛岀浉瀵规潵璇达紝杩欏氨澧炲姞浜嗘湰棰樼殑闅惧害锛岃鐭ラ亾锛4涔樹互6绛変簬24锛屼腑闂寸殑5濡備綍澶勭悊灏辨槸鏈鐨勫叧閿偣锛岄偅鍙互杩愮敤C璇█鐨勫彇妯¤繍绠楃鈥%鈥濊繘琛屽彇妯¤繍绠椼傚彇妯¤繍绠楃鈥%鈥濈殑浣滅敤鏄眰涓や釜鏁...
绛旓細瑙ｆ瀽锛氶噰鐢ㄦ媶鍒嗘硶锛岀劧鍚庢牴鎹箻娉曠粨鍚堝緥杩涜璁＄畻鍗冲彲銆25脳24 =25脳4脳6锛堝皢24鎷嗗垎鎴4脳6锛=100脳6锛堝皢25鍜4鐩镐箻寰楀埌鏁寸櫨鏁帮紝浣胯绠楃畝鍗曞寲锛=600 涔樻硶缁撳悎寰嬬敤瀛楁瘝琛ㄧず涓(a脳b)脳c=a脳(b脳c)锛屽畠鐨勫畾涔夛紙鏂规硶锛夋槸锛氫笁涓暟鐩镐箻锛屽厛鎶婂墠涓や釜鏁扮浉涔橈紝鍐嶅拰绗笁涓暟鐩镐箻锛涙垨鍏堟妸鍚庝袱涓暟鐩镐箻...
绛旓細24梅5=4.8
绛旓細鍥炵瓟锛27涔4涔榵5绠渚胯繍绠楁柟娉曟槸; 27x4X5 =27x20 =540 杩欏氨鏄27涔4涔5鐨勭畝渚胯繍绠楁柟娉,璁＄畻缁撴灉绛変簬540銆
