Number & Operations in Base Ten

November 20, 2019
Base 10 Blocks

Base Ten Blocks

This is a school term, sometimes used in teaching math. The word has no formal mathematical definition. A model for base 10 numeration. Ten copies of […]
November 20, 2019


The terms factor and multiple are sometimes confused with each other. Factors of 15 include 3 and 5; multiples of 15 include 30, 45, 60 (and […]
November 20, 2019

Prime Numbers

Any counting number, other than 1, can be built by adding two or more smaller counting numbers. But only some counting numbers can be composed by multiplying two or more smaller counting numbers.
November 20, 2019

Algebraic Thinking

Number tricks are fun for children. The fun, all by itself, is valuable, but is not mathematics. But understanding how the trick works is good mathematical, often algebraic, learning.
November 20, 2019
KenKen puzzle

Puzzles: Introducing KenKen Puzzles

This page focuses on a way to introduce KenKen puzzles so that students see, focus on, and learn the logic, not just guessing. These puzzles give […]
November 20, 2019


Question: Children (and adults) are often uncertain whether the multiples of, say, 12 are the numbers one can multiply (like 3 and 4) to make 12, […]