{#blank#}1{#/blank#}个{#blank#}2{#/blank#}                    {#blank#}3{#/blank#}×{#blank#}4{#/blank#}

三{#blank#}1{#/blank#}二十一   五七{#blank#}2{#/blank#}   四七{#blank#}3{#/blank#}

6的3倍是{#blank#}2{#/blank#}．

8是4的{#blank#}3{#/blank#}倍．

4个2相加                                            2×4=8

6+6+6                       4×2                  5乘4

4 + 4+4 +4 +4           6×3                 乘数是6和3

3+3+3+3+3+3           5×4                 2+2+2+2

5 +5 + 5 +5                                        3×6

2乘4                                                    4×5