The teen numbers are the hardest stretch in early counting because their names break the pattern — eleven and twelve sound like nothing else, and thirteen through nineteen reverse the order you say them in. This deck gives each one its own card, spoken clearly, so the irregular names get heard often enough to stick.
Eleven and twelve give no clue to their value, and thirteen through nineteen say the ones digit before the tens. Children who count to ten confidently often stall here, which is normal.
Two or three minutes is plenty at this age. Short daily runs beat one long session.
Still counting to ten? Start a rung lower with the Counting flashcards · all ages 3-4 activities