24*99-1又3/8*644.6+588.8*（-1又3/8）+233.4*11/8
=24×99-（1+3/8）×644.6+588.8×（-1-3/8）+233.4×11/8
=24×99-11/8×644.6-588.8×11/8+233.4×11/8
=24×99-11/8×﹙644.6+588.8-233.4﹚
=24×99-11/8×﹙644.6-233.4+588.8﹚
=24×99-11/8×﹙411.2+588.8﹚
=24×99-11/8×1000
=24×9×11-11×125
=﹙24×10-24-125﹚×11
=91×11
=90×11+11
=990+11
=1001