【導讀】Let’slearn!fourthreetwoonewo. five. one. Let’splay!Let’scount!two+three=five. four+four=eight. six+one=seven. five+five=ten. one+three=. four+five=. two+six=. seven-three=. eight+one=. two+two=. nine+one=. eight-five=. six+three=. four-three=. four. nine. eight. four. nine. four. ten. three. nine. one