The Calculator Duo journal

A little help with the everyday math.

Practical guides for clearer calculations, from percentages to your next project estimate.

Learn how a tape calculator keeps your steps visible, helps you check totals, and makes repeated calculations easier to understand.

Calculate percentage increases and discounts with clear examples. Learn why a 20% discount and a 20% increase do not cancel each other out.

Build an understandable project estimate with quantity × unit price. See a worked example using hours, materials, and a fixed cost.

Make room for your next good idea.

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