Count with ten strips to 20
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Count with ten strips to 20: skill guide
| Objective | This practice uses two horizontal ten strips to show quantities from 11 to 20. |
|---|---|
| Grade | Kindergarten |
| Standard | CCSS.MATH.CONTENT.K.CC.B.5 |
| Difficulty | Foundational · Mixed |
| Representation | Ten strip, Number sequence |
| Practice format | Interactive, account-free practice with immediate feedback |
Objective
This practice uses two horizontal ten strips to show quantities from 11 to 20.
What this practice covers
This practice uses two horizontal ten strips to show quantities from 11 to 20. The first strip is full, making one group of ten visible, while the second strip shows the additional ones. Learners can count on from ten rather than recounting every dot. The midpoint line on each strip preserves five as another useful landmark.
Standards alignment
Supports Common Core: CCSS.MATH.CONTENT.K.CC.B.5 — Count to answer ‘how many?’ questions about as many as 20 arranged objects.
Who it’s for
It is designed for kindergarten learners who count through twenty and recognize quantities through ten. It supports the transition from counting individual objects to seeing teen numbers as one ten and some more ones.
What to know first
- Learners should recognize a full ten strip as 10, count forward from 10 to 20, and understand that each added dot increases the amount by one. Place-value vocabulary is helpful but not required.
Difficulty and scaffolding
Foundational · Mixed stage
Problem representations
- Ten strip
- Number sequence
Three worked examples
- One full strip and 1 more dot show 11.
- One full strip and 4 more dots show 14.
- Two full strips show 20.
Likely misconceptions
- Learners may restart at one on the second strip and report only the extra ones, or recount both strips from the beginning. Name the first full strip as ten, then count on the additional dots: eleven, twelve, and so on. Check that answers fall between 11 and 20.
Hints and explanations
- One full strip and 1 more dot show 11.
- One full strip and 4 more dots show 14.
- Two full strips show 20.
What to practice next
Find complements of 20 by splitting two full strips into red and green parts. Then build the same teen numbers with one ten rod and individual unit blocks.
Editorial review
Reviewed by Brilliant’s curriculum team. Exercises are generated within defined difficulty ranges and checked against verified answer rules.
Count with ten strips to 20 FAQs
Why use two ten strips?
Two strips make the structure of teen numbers visible. One full strip represents ten, and the second shows how many ones are added. This supports early place-value thinking.
Should a learner count every dot?
They may count at first, but the intended strategy is to recognize the full strip as ten and count on only the dots in the second strip. This is faster and highlights number structure.
How is 16 shown?
The first strip contains ten dots. The second contains six more dots, so the complete model shows 10 + 6 = 16.
What should come after this practice?
Use two-color strips to find pairs that make 20, then represent teen numbers with a ten rod and unit cubes. Both activities reinforce one ten plus some ones.