+=7 +=7 +=7
+=7 +=7
(只)
4+3= 2+2= 0+7= 6-5=
7-5= 6-1= 1+6= 2+3=
4+1= 6-4= 7-6= 5-0=
3+3= 5-2= 7-1= 7-4=