For K–3 teachers & interventionists

Welcome to DotSense.
Free, zero-prep number sense tools for teachers.

Every tool is a full instructional routine, not just a manipulative. They are evidence-based and built for how young students develop number sense.

How it works

One simple routine, every tool

The same four steps that make number talks work. Timing, prompts, and projection mode are handled for you.

1 · Flash

A quick image appears just long enough to see, not count — so students reason about quantity instead of counting by ones.

2 · Wait

The image hides. Quiet think time lets every student form an answer before anyone speaks.

3 · Ask

"How did you see it?" A rotating prompt invites students to share the strategy behind their answer.

4 · Reveal

The image returns — often animated — to confirm the answer and make the strategy visible to the whole class.

Tool suite

The tool suite

Every tool below is free and open, no login required today. No student accounts. No student data. Ever.

Number Sense

Grades K–2

Subitizing Free

Flash grouped dots, ten frames, dice, and finger patterns. The flagship routine that started it all.

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Grades K–3

Choral Counting Free

Count by 1s, 5s, or 10s, forward or backward — the track accumulates so the class sees the pattern build, row by row.

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Fractions

Grades 3–5 · flagship

Fraction Number Line Free

Place fractions on lines that run past one whole — improper fractions and mixed numbers by default.

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Grades 3–5 · bias-buster

Fraction Compare Free

Compare two fractions by magnitude, never by cross-multiplying — presets target exactly where whole-number bias shows up.

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Fluency

Grades 2–3

Multi-Digit Strategy Flash Free

Addition and subtraction up to 1000, using the same named strategies as Fact Fluency Strategy Flash — extended to a new number range and visual model.

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Grades 1–3

Fact Fluency Strategy Flash Free

Doubles, near doubles, make ten, using ten — every reveal shows the visual model behind the strategy, never a naked timer. Already live on Number Sense.

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New: Fraction Routines

A whole second suite — number line, equal sharing, unit-fraction building, magnitude comparison, and multi-model flash — all designed to prevent and dislodge whole-number bias. For grades 1–5.

Explore fractions →