This set of blocks will help students learn how to think about the logarithmic relationships between integers and connect these facts to operations like multiplication, factorization, and the sequence of primes.
Linearly stacking blocks (on their side) and comparing their total length against a log scale (or other stacks) will reinforce concepts of prime factors and integer uniqueness.
Some lesson ideas are included in the instructions.
v2 note: The blocks stack better now. They're also a good exercise in resolution and dynamic range... or lack of it. These are best for instruction rather than actual calculation.
Blocks for logarithms, multiplication, factors, and primes: The Logprimus by seedwire is licensed under the Creative Commons - Attribution - Share Alike license.