简便计算
47x510-470
=470x51-470
=470×(51-1)
=470×50
=23500
原式=470*(51-1)
=470*50
=400*50+70*50
=20000+3500
=23500
47ⅹ510-470
=470ⅹ51-470
=470x(51-1)
=470x50
=23500
=47*10*51-470
=470*51-470
=470*(51-1)
我好闲啊
47x510-470
=470x51-470
=470×(51-1)
=470×50
=23500