1*2*3*4*······*48*49*50的积的末尾一共有多少个0?不仅要解释,还要算式,一定要简单一点,小学生能看得懂的那一种

1 2 3 4 ·····7 ·······10 ········?1 3 5 7 ·····?······?··········290 1 4 9 ·····?······?··········? 8+11+14+17+20+·······+305 数学计算题.呜呜呜1+2+3+4+···················+98+99+100+99+98+···············+3+2+1 50+49-48-47+46+45-44-43+······-4-3+2+1=? 计算1+(2+3)-(4+5)+(6+7)-(8+9)······-(48+49)+50= 巧算1*2+2*3+3*4+······+49*50=? 1+1/1+2+1/1+2+3······+1/1+2+3+4+5+6······+46+47+48+49+50得多少? 急·····················1+2+3+...+999=? 俗语和名句的填空1······,自知之明.2······,行必果.3工欲善其事,······.4临渊羡鱼,······.5非学无以广才,······.6······,福兮祸之所伏.7项庄舞剑,······.8······,人以群 2[4/3y—（2/3y—1/2）]=3/4y急·································!1 计算1/（1*4）+1/（4*7）+1/（7*10)+------+1/(97*100)································································································ 证明1·3·5·····(2n-1)/2·4·6·····2n 1+2+3+4+5+6+7+8+9+1+11+12+13+14+15````````1+2+3+4+5+6+7+8+9+1+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26+27+28++29+30+31+32+33+34+35+36+37+38+39+40+41+42+43+44+45+46+47+48+49+50·································· 1+2++3+··········+10000= 观察下列三角形数表其中从第二行起每行的每一个数为其肩膀上两树之和则该表的最后一个数是?1 2 3 4 5 6 7 8················ 97 98 99 100 3 5 7·························· 计算题：50+49-48+47-46+···-4+3-2+1 全部属于裸子植物的是 1卷柏 2侧柏 3银杏 4刺槐 5苏铁 6梧桐 7云杉 8贯从 9珙桐 A1237 B2357 C2379 D1358贯从是贯众······························· （-1）×2×（-3）×4×···×（-49）×50/2×4×6×···×100 2011红领巾快乐数独答案一2·····4·9·631·4·8·8··97··3··3··2·95···95·86···15·3··7··9··47··5·7·3·182·3·4·····7二7·1·8·3·····413·6·2·6···4·8·8·5·1·2·61·····94·2·9·4·7·8·