Number Sense

Teen numbers are one of the most commonly misunderstood number ranges for Foundation and Year 1 students. That’s why we’ve created a collection of fun activities and printable worksheets designed to build strong number sense, connect quantity to place value, and support the learning of numbers 11 to 19.

Why Teen Numbers Are So Tricky

Teen numbers follow irregular naming patterns, which can confuse early learners. For example:

• 11 and 12 don’t follow the ten-and-some-more structure
• 13–19 have inconsistent word formations (thir-teen, fif-teen)
• Students often confuse teen and ty numbers (e.g., 14 vs 40)
• They struggle to understand that 13 = 10 + 3, not just “three”

Hands-On Activities First: Build Understanding Before Practice

Before jumping into worksheets, build conceptual understanding with hands-on materials such as:

• Base ten blocks – Show 10 + ___ structure
• Ten frames – Reinforce subitising and counting
• Counting beads or pop sticks – Group into 10s and extras
• Number towers or linking cubes – Build and compare lengths
• Number cards and numeral puzzles – Match words, digits, and quantities

These tools give students the concrete experiences needed to visualise and reason about the teen numbers.

These worksheets support both differentiated instruction and ongoing assessment in line with Australian Curriculum v9 outcomes for Number and Algebra.

Link Confusion with -ty Numbers

Students often mix up teen numbers with multiples of ten like twenty, thirty, forty etc. For more help with this, check out our –ty Number Resources, which address this specific confusion through comparison games and visuals.

Use in the Classroom

These activities are ideal for:

• Small group rotations
• Maths stations
• Homework tasks
• Assessment snapshots
• Intervention and extension groups

Each resource is designed to be low-prep, engaging, and aligned with the Australian Curriculum v9 Foundation and Year 1 achievement standards.

Wrap-Up

Understanding teen numbers is a big milestone in early maths. Our printable worksheets and hands-on activities help make this tricky number range more concrete and manageable. Download them today and watch your students build confidence in counting, place value and number recognition!