Grandpa used orange segments to teach his grandson math, and the process was very crazy... Netizens: I feel sorry for the grandpa for a second. 姥爷用橘子瓣给外孙上数学课，过程很抓狂......网友：心疼姥爷一秒。（素材来源：抖音@羊头） | People's Daily,Overseas

We teach it simply: shoulder → elbow → hand. The shoulder carries the weight of the arm, so effort should start there — not from the hand. When the shoulder moves first, the arm works in segments, creating whip. When you move from the hand, the arm becomes one stiff piece, and you lose both whip and line. | PowerhouseMechanics