Unit writing in elementary school mathematics application problems

In the calculation process, generally, the unit is not written first, and brackets are added after the final result, and the name of the unit is written in brackets. If there are writing units in the formula, do not put brackets around the units of the final result.

(1) Xiaoming is 10 years old this year. He is five years younger than his sister. How old is Xiaoming's sister this year?

10+5= 15 (years old)

(2) Xiaoming and Xiaohua jump rope. Xiaoming jumped 89 times in 1 min, 9 times more than Xiaohua, and Xiaohua jumped several times in 1 min.

89 Stroke -9 Stroke =80 Stroke