9×=45 4×=36 ×9=63
9×=9 ×9=72 5×=40
例:
7盒有多少个?8盒、9盒呢?
8×4= 9×7 = 2×8= 7×8 – 8 =
8×9= 4×6= 9×8= 2×9+9=
8×2= 4×9= 8×7= 1 ×8 – 8 =
9×3 = 8×3 = 2×9= 8×6 =
80 – 59 = 35 + 49 = 77 – 77 = 9+76 =
元