加拿大温沙大学:一道五年级简便运算

来源:百度文库 编辑:查人人中国名人网 时间:2024/05/06 17:02:19
9999乘9999加19999
简便运算
写出具体步骤

9999*9999+19999
=9999*(10000-1)+19999
=99990000-9999+19999
=99990000+10000
=100000000

原式=9999*9999+9999+10000
=9999*(9999+1)+10000
=9999*10000+10000
=(9999+1)*10000
=10000*10000
=100000000

9999*9999+19999
=(10000-1)*9999+19999
=99990000-9999+10000+9999
=99990000+10000
=100000000

9999*9999+19999
=(10000-1)*9999+19999
=99990000-9999+10000+9999
=99990000+10000
=100000000

原式=(10000-1)的平方+19999
=100000000-20000+1+19999
=99980001+19999
=100000000

(10000-1)*9999+10000+9999=99990000-9999+10000+9999=99990000+10000=100000000