Question

两道小学生的奥数题，帮忙解一下

8.4321×12345=

8.4322×12344=

两道用简便运算算出来……实在是难啊，哪位高手帮个忙。记住，是简便运算，要小学生看得懂的……
是比较大小，不是简便运算……我弄错了……恩恩，补充一下。是比较两个算式结果的大小……简便较快地比较大小……

Answer 1

8.4321×12345
=8.4321×(12344+1)
=8.4321×12344+8.4321

8.4322×12344
=(8.4321-0.0001)×12344
=8.4321×12344-1.2344

8.4321×12344+8.4321＞8.4321×12344-1.2344 所以8.4321×12345＞8.4322×12344

Answer 2

楼上的符号错了
8.4321×12345=8.4321×(12344+1)=（8.4321×12344)+8.4321 (1)
8.4322×12344=(8.4321+0.0001)×12344=(8.4321×12344）+1.2344 (2)

因为8.4321>1.2344
所以（1)>(2)
既8.4321×12345>8.4322×12344

Answer 3

8.4321×12345=8.4321×(12344+1)=8.4321×12344+8.4321 (1)
8.4322×12344=(8.4321-0.0001)×12344=8.4321×12344-1.2344 (2)

所以（1）>（2）
你不会是小学老师把

Answer 4

8.4321*(12344+1)=8.4321*12344+8.4321

(8.4321+0.0001*12344
=8.4321*12344+8.4321*0.0001
8.4321×12345>8.4322×12344

Answer 5

8.4321 X 12345 = 8.4321 X (12344 + 1)=8.4321 X 12344 + 8.4321
8.4322 X 12344 = (8.4321 + 0.0001) X 12344=8.4321 X 12344 + 1.2344

因为 8.4321>1.2344
则 8.4321 X 12345 > 8.4322 X 12344