half hour in a math article buys you 0-10 lines depending on the article and how experienced you are at reading mathematics. There is no substitute for work and time.  You can speed up your math reading skill by practicing, but be careful.  Like any skill, trying too much too fast can set you back and kill your motivation.  Imagine trying to do an hour of high-energy aerobics if you have not worked out in two years.  You may make it through the first class, but you are not likely to come back.  The frustration from seeing the experienced class members effortlessly do twice as much as you, while you moan the whole next day from soreness, is too much to take.