21:56=8分之3=12÷()=()
21:56=8分之3=12÷(32)=(0.375)
例:9:16 sixteen minutes past nine求:7:34 12:01 15:09 1:56 17:21
thirty four past seven
one past twelve
nine past fifteen
four to two
twentyone past five p.m.
能簡算的簡算(五分之二+六分之一-十五分之二)×30
能簡算的簡算
(五分之二+六分之一-十五分之二)×30
2/5×30+1/6×30-2/15×30,完了可以約分