2+2+2+2 4×2 2个3相加
3×2 5×3 2×4
3+3+3+3+3 2×3 乘数是3和5
12+12+12+12:□〇□
7和9相加:□〇□
两个乘数都是8:□〇□
7个9相加:□〇□
加法算式:
乘法算式:
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