20% of 20 =
                   ( 4 )

10% of 50 =
                   (       )

20% of 10 =
                   (       )

60% of 60 =
                   (       )

10% of 90 =
                   (       )

20% of 70 =
                   (       )

30% of 30 =
                   (       )

70% of 80 =
                   (       )

20% of 20 =
                   (       )

          +[         ]

10% of 40 =
                   ( 4 )

20% of 90 =
                   (       )

60% of 50 =
                   (       )

40% of 20 =
                   (       )

20% of 60 =
                   (       )

30% of 10 =
                   (       )

70% of 60 =
                   (       )

20% of 90 =
                   (       )

30% of 70 =
                   (       )

          +[         ]

40% of 20 =
                   ( 8 )

80% of 70 =
                   (       )

40% of 10 =
                   (       )

20% of 40 =
                   (       )

60% of 30 =
                   (       )

70% of 50 =
                   (       )

50% of 20 =
                   (       )

30% of 50 =
                   (       )

50% of 10 =
                   (       )

          +[         ]

       ++[[            ]]