Physics

At age five, Zack did not get homework, so he helped his brothers and sisters with theirs. He looked at the paper his seventeen year old brother Joe was squinting at, covered in letters and numbers.

"What is this?"

Joe looked down at him. "It's math," he simplified.

"No it's not. You're using Young's modulus," Zack glared.

Joe looked surprised. "Okay, it's physics."

"Here's your problem." Zack's little fingers took the pencil. "You raised to the tenth instead of the ninth." He corrected the equation with thick, messy numbers and went around the table to help Deborah with her spelling.