Gurudev, I feel very sleepy during Mathematics classes. What could be the reason for this? Also, what can I do to increase my concentration in those classes?
This is simply because you do not have much interest in Maths. That is why this happens. Also, one does feel a bit sleepy immediately after meals. So, to become sharper at Maths, you must sit and solve more math problems. When you sit to solve problems using a pen and paper, then you will not feel sleepy. If you sit to read something then it is possible to feel sleepy, or when you are listening to something. When you are working on something then you will not feel sleepy.
Also, develop a habit of studying such subjects when your mind is fresh, like in the mornings. See, children are of two types, according to study habits.
1. Those who wakeup early in the morning to study
2. Those who stay up late in the night to finish studies
So first you must decide what your type of study habit is. Even those who have a habit of studying in the night should not stay up later than 1 AM or 2 AM. I know this because I too used to like studying at night time. So this depends on our type. Some people like to study in the early morning when it is fresh and bright outside.
You should also pay careful attention to your food. If you have a stuffed Parantha (a type of Indian bread) and a glassful of Lassi (a thick yogurt-based drink), then you are sure to feel sleepy. So you should keep your food light and nutritious. Have more of raw vegetables and salads. Reduce the quantity of food grains, cereals, and sweets. This also helps increase your alertness.