I taught N number sequence using flashcards when he was little, but i only taught him up to 50. I recently realised while he knows what comes next after 50, but he doesn't know what comes after 59, 69,79, 89 and 99.
Hence i created this activity using the 'BEFORE & AFTER' activity we did last week. I first presented to him by showing him that 60 comes after 59 etc. We're going to repeat this activity till im certain he got it.