Answers

2016-06-20T17:41:54+08:00
a method or process of numbering, counting, or computing.
example: 
Lita is 7 years older than her sister lyn. In 8 years, the sum of their ages will be 29. How old is Lita now?
Answer:
29-7=22
÷2 (lita and lyn)=11 
11+7 (older)=18             18-8 years=10 (lita)
11                =11
                  --------
                     29
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