Build numbers using base-ten blocks! Tap to add tens (orange) and ones (blue) blocks to match a target number. Visual stacking reinforces place value understanding for numbers up to 99.
Choose Difficulty and Mode
Pick Easy (1–20), Medium (1–50), or Hard (1–99). Then select 60-Second Build or Survival (3 lives).
See the Target Number
A large target number appears at the top (for example 47). Your job is to build it with blocks.
Add Blocks
Tap '+ Ten' to add an orange ten-block and '+ One' to add a blue unit block. Use '−' buttons to remove if you overshoot. Watch the running total update.
Submit Your Build
When your total matches the target, hit Check! Green means correct. Keep building numbers to grow your score!
Visual Base-Ten Blocks
Orange blocks represent tens and smaller blue blocks represent ones. Watch them appear as you tap, giving a concrete visual of how numbers are composed from place-value parts.
Three Difficulty Levels
Easy mode uses numbers 1–20 (great for learning). Medium goes up to 50 for more tens practice. Hard covers the full range 1–99, requiring confident place-value decomposition.
60-Second Build and Survival Modes
In Build mode, compose as many numbers as possible before time runs out. In Survival mode you have 3 lives — submit the wrong number and lose one.
Instant Feedback with Totals
A running total shows your current build in real time, turning green when it matches the target. After submitting, the correct decomposition is shown if you were wrong.
Tens and Ones is a place-value game that makes abstract number concepts concrete. Students see a target number and build it by adding base-ten blocks — large orange blocks worth 10 each and small blue blocks worth 1. A live counter shows the running total so students can self-correct before submitting. This mirrors the physical base-ten block manipulatives used in classrooms worldwide but adds gamification through timed rounds, score streaks, and difficulty levels.
Builds Place-Value Intuition
Repeatedly composing and decomposing two-digit numbers ingrains the idea that '47' is not just a label — it's 4 tens and 7 ones. This understanding is critical for addition, subtraction, and later multi-digit operations.
Connects to Classroom Manipulatives
Base-ten blocks are a cornerstone of early math instruction. This digital version lets students practice at home with the same visual model their teacher uses in class.
Self-Correcting Design
The live total turns green when correct, encouraging students to check their work before submitting — building metacognitive skills alongside math facts.
Scaffolded Difficulty
Easy mode only goes to 20 (mostly ones practice). Medium introduces more tens. Hard covers the full 1–99 range, letting teachers assign the right level for each student.
Base-ten blocks (also called Dienes blocks) are manipulatives where small cubes represent 1, rods represent 10, flats represent 100, and large cubes represent 1000. This game uses the rod (ten) and cube (one) to build two-digit numbers.
No — each place value column is limited to 0–9 blocks, matching how our number system works. If you need more, add a ten block instead. This reinforces regrouping concepts.
You'll see a red feedback message showing the correct decomposition (e.g., '4 tens + 7 ones'). In Survival mode you also lose a life. In Timed mode there's no life penalty — just try again quickly.
Yes. Your best score is saved locally in your browser for each combination of difficulty and game mode. It's shown on the settings screen.
Tens and Ones is designed for children in grades K–2 (ages 5–8) who are learning place value. Easy mode is great for kindergartners, while Hard mode challenges second graders.