blackboard

drawing

small

activity

person

one

child

boy

education

cute

preschool

people

elementary

indoors

human

classroom

equipment

school

learning

innocence

back

blue

white

university

inside

alone

shirt

complex

equation

mathematics

formula

quantum

physics

optics

integral

function

caucasian

solve

addition

simply

turn

answer

write

result

number

two

mistake

think

chalk