英文關鍵字
abacus
addition
arithmetic
baby
boy
calculation
caucasian
child
count
decision
difficulties
doing
education
elementary
exam
example
examples
exercise
exercises
floor
grade
home
homeschooling
homework
indoors
kid
kids
knowledge
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learning
lesson
logic
math
mathematics
numbers
prepare
preparing
preschool
preschooler
problems
remember
remote
school
schoolboy
schooleducation
simple
skill
solve
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student
study
subtraction
task
test
textbook
think
tutorial
workbook
write