Significant figures in lab reports
Carry adequate precision through calculations and round the reported result once using the rule required by the operation or course.
Counting significant figures
Leading zeros are placeholders; zeros between non-zero digits are significant; trailing zeros require context or explicit decimal notation.
Operation rules differ
Multiplication and division commonly follow the least-significant-figures input. Addition and subtraction commonly follow the least precise decimal place.
Keep guard digits
Do not round every intermediate step. Preserve extra digits in the calculation trace and round the final reported result to avoid accumulated rounding drift.
Uncertainty can be the better owner
When measurement uncertainty is estimated, it often determines the useful reporting precision. Follow your course or lab convention rather than applying a mechanical rule blindly.
Sources and boundaries
Solice develops LabCrux. The independent sources above do not sponsor or endorse the product. This page explains a review method; your experimental evidence, course instructions, and instructor remain authoritative.