409=49 182=16 307=37
433=40 205=25 533=50
11-38 16-78 12-67
16-79 915-7 17-89
12-717-9 13-811-6 12-311-4
写作: , 读作:
5+35=
13-8=
20+6=
77-7=
54-4=
95-90=
27+4=
48-9=
88+5=
64+30=
7+53+10=
90-40-30=
13-(4+5)=
3+(3+40)=