Keke practices math online after shcool every day.

This is an assignment by her teacher.

The first day when she was working on it, 非常有趣。 一道加法必须在有限时间答完，可可手指头飞快的动着，十以上的加法在拼命的数加几个。 后来熟悉些了，尽管不明显了，手指头也在悄悄的动。