52=7 123=4 55=25
427=6 73=10 189=9
写作:
读作:
(1,10,2),(2,20,4),(3,30,6),
50>×7 21>4× 8×<54
4×<35 5×<48 9×<22+45
78-27=
54-31=
27-18=
27+31=
24+57=
9+36=
2﹣30%= +25%= 4.23﹣23%= ×=
3+= 4×15%= = +50%=
A.
B.
C.