Blog

Math that makes sense.

Teacher-friendly posts about K-8 math, visualized with bar models, number lines, and precise language rooted in 40+ years of research.

24 posts
Measurement

Can Perimeter Be Larger Than Area?

Yes. And your students probably think it's impossible. Here's why that's actually a great conversation starter.

Fractions

Understanding Fractions: Visual Models That Build Durable Learning

Fractions are a count of equal units. Bar models and number lines make this visible. No rules to memorize, just math that makes sense.

Number Fluency

Subtraction with Regrouping: Forget Borrowing, Try Exchanging

"Borrow" implies you'll give it back. Exchanging captures what actually happens when we decompose units.

Operations

The Power of Division: Sharing Equally vs. How Many Groups

Division looks like one operation from the outside. Inside, it's two very different problems wearing the same mask.

Number Sense

Building Place Value Proficiency

Filling in columns isn't understanding. True proficiency means knowing how units compose and decompose across positions.

Math Foundations

Facts vs. Fluency: What Students Actually Need

Timed tests create two groups: those who can answer fast and those who've been told they're bad at math.

Proportional Reasoning

Ratio Tables: Building Multiplicative Thinking

A ratio table isn't just a grid. It's the bridge from additive thinking to proportional reasoning.

Problem Solving

Why Students Struggle With Word Problems (And How Bar Models Help)

Most word problems aren't math problems. They're translation problems. Bar models fix that.

Teaching & Assessment

What "Depth of Knowledge" Actually Means

DOK isn't about difficulty. It's about cognitive demand: how deeply students need to think, not just compute.

Fractions

Multiplying Fractions: Why the Answer Gets Smaller

Multiply straight across is the easiest rule in the unit and the least understood. One square, two partitions, and it makes sense.

Fractions

Dividing Fractions: Why "Flip and Multiply" Actually Works

Keep, change, flip works, and almost no student knows why. Division asks how many units fit. Count them and the rule falls out.

Operations

How to Teach Multiplication Conceptually

Memorized facts answer 7 times 8. Structure answers 7 times 80, 7 times 0.8, and 7 times two-thirds. Here's how to build structure.

Visual Models

Why Number Lines Should Be Built, Not Handed Out

The strip above your whiteboard teaches students to read labels. A line they build teaches them to measure.

Early Number Sense

The Counting Principles: Why Reciting Numbers Isn't Counting

A child who counts to 100 may still not know how many bears are on the table. Those are two different skills.

Intervention

Reteaching That Works: Diagnose First, Then Change the Route

Reteaching the same lesson slower is the one approach that reliably fails. Diagnose the specific gap, rebuild it with a model, then show the same problem a second way.

Number Sense

What Number Sense Actually Is (And How to Build It)

Number sense is not speed and it is not a trait. It is three teachable habits: decomposing toward benchmarks, shifting units, and estimating before computing.

Measurement

Teaching Measurement Conceptually: Iterate, Then Partition

Students who measure from the 1 mark instead of 0 are not careless. They learned that measuring means reading the endpoint. Here is how to teach it differently.

Decimals

Teaching Decimals: Why 0.45 Is Not Bigger Than 0.7

Students who say 0.45 is larger than 0.7 are applying a whole number rule. Teach decimals as a count of units on a number line and comparison follows.

Teaching Practice

Math Manipulatives: The Step Between Blocks and Numbers

Students build 24 with blocks on Tuesday and can do nothing with 24 on Wednesday. The missing step is the drawing in between.

Fractions

Equivalent Fractions: Same Amount, Different Units

If you multiply the top and the bottom, why doesn't it get bigger? Because nothing was multiplied. The amount was repartitioned.

Fractions

Adding and Subtracting Fractions With Unlike Denominators

Two-thirds plus one-fourth isn't three-sevenths for the same reason 2 feet plus 1 inch isn't 3 of anything.

Fractions

Comparing and Ordering Fractions Without Cross Multiplying

A student who knows what the two numbers mean can usually compare fractions without computing anything at all.

Fractions

Mixed Numbers and Improper Fractions: One Amount, Two Names

Converting isn't a calculation. It's composing units into 1s, the same exchange students already know from place value.

Operations

How to Teach Long Division So the Steps Make Sense

Ask what the 2 above the tens column is worth, not what it is. Most students say two. It's worth twenty.