6·2×0·99用简算

6·2×0·99用简算 计算1-2+3-4+5-6+······+99-100= 计算：(2+4+6+8+···+100)-(1+3+5+···+99) 计算1-2+3-4+5-6+······-98+99= (2+4+6+8+······+100)—(1+3+5+7+······+99)等于几 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·························· 0·99×4·6简便计算 0·8×（3·2-2·99÷2·3）简算 1-2+3-4+5-6+7-8+9······+99-100 1+2+3+4+5+6+7+8+9······+99=?1 1+2-3+4+5-6······+97+98-99的解题方法是巧算快 1+2···+99 (1+3+5+7+·····+99+101)—(2+4+6+8+····+98+100) 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 0·99×99+0·99怎样简算? 1+2+3+4+······+78+79+801/2+1/6+1/12+1/20+······+1/72+1/90100-99+98-97+96-······+4-3+2-11000-1-2-3-4-······-78-79-801/15+2/15+······+13/15+14/15注：例 1/15 就是 十五分之一 只用+号,把1·2·3·4·5·6·7·8·9凑成99 只用+号,把1·2·3·4·5·6·7·8·9凑成99