1.   Circles

Luhan:: 11 years old

Sehun:: 7 years old

"Hyung! What is six plus nine?" Luhan turned his head and saw his little brother come running towards him with a piece of paper and a pencil in his small hand. "Hyung! Teach me!"

Acting like how a big brother was supposed to be, Luhan motioned the younger boy to sit down by his side and took the pencil in his own hands, "Sehun-a, you just have to draw circles like this..." then he started making round shapes on the paper slowly, "Look, one, two, three, four ,five, and six!"

"And there you have six circles. Now if you draw another nine circles, you can count them together." Luhan smiled and handed the pencil and paper back to Sehun.

"Okay! One, two, three..." little Sehun guided the tip of the pencil and created some wiggling circle-like shapes, "six, seven... hmm, seven..." he stopped and scratched the back of his head as he tried hard to remember what came after seven. Then he tugged at his hyung's sleeves again.

"Hyung, what comes after seven?"

"Eight." Luhan didn't turn this time as he worked on his own homework. He was in the fifth grade of elementary school and things were different for him and his first-grade brother. He was dealing with fractions while Sehun was still trying to count from one to fifty.

"Thanks! Seven, eight, nine." Sehun grinned brightly when he finished the last couple of circles on his piece of paper. "Now what do I do, hyung?"

"Count all the circles together. You'll get six plus nine." Luhan replied as he gestured on where the paper had been drawn, "Can you do it?"

"Yes, of course! Lemme count!" Sehun nodded and put his index finger onto the circles one by one, "One, two, three...  ten, eleven, twelve... Uh, hyung?"

"Yeah?"

"What comes after twelve?"

"Thirteen."

"Oh. Thirteen, fourteen, fifteen, sixteen, seve