2-4/9×3/8
=2-1/9×3/2
=2-1/6
=11/6
60×(1/4+4/15+3/20)
=60×1/4+60×4/15+60×3/20
=15+16+9
=40
444×4/443
=(443+1)×4/443
=443×4/443+4/443
=4+4/443
=4又4/443
2-4/9×3/8
=2-1/9×3/2
=2-1/6
=11/6
60×(1/4+4/15+3/20)
=60×1/4+60×4/15+60×3/20
=15+16+9
=40
444×4/443
=(443+1)×4/443
=443×4/443+4/443
=4+4/443
=4又4/443