I have always thought that mathematics can't be done by doing problems. Methods are always more important than simply doing problems. Before the lecture the next day, I'd better preview a photo in my drawer, which is my family photo, including my parents, grandparents and me who is only seven years old. In the photo, there is a familiar face. He is my grandfather. His thin face looks grim and doesn't like to talk. His forehead is engraved with deep wrinkles, leaving traces of years. Touching grandpa's face, tears flashed in my eyes again, and I recalled everything before ... "Hehe ..." When I was a freshman, I sat on grandpa's bike and smiled happily. Grandpa was in front, I was behind, and I rode to Lianhua Lake. A row of wicker came with the wind, and grandpa picked one and handed it to me. It was still early, so grandpa stopped his bike, took my little hand and sat in the chair, teaching me to weave wicker and fold hats. "Look, bend it again and then do it in order, and finally tie a knot," Grandpa said with a smile. I learned to weave wicker hats like grandpa, but I still can't. In a short time, grandpa's wicker hat was ready.