英文關鍵字
add
addition
arithmetic
basic
black
blackboard
board
chalk
chalkboard
child
class
classroom
clever
concept
decision
demonstrate
educate
education
elementary
equals
equation
example
figures
four
hand
idea
kid
kindergarten
learn
lesson
math
mathematical
mathematics
numbers
plus
practice
problem
school
simple
student
study
survey
teach
teacher
two
write
writing