You have 9 sets and you have 10 sets. If you join the 10 to the 9 and count them all... you will have a total of 19. So 9+10 equals 19
You have 9 sets and you have 10 sets. If you join the 10 to the 9 and count them all... you will have a total of 19. So 9+10 equals 19