Significant Figures Quiz: Test Your Scientific Measurement Skills

Significant figures communicate measurement precision. They tell which digits are reliable and which are uncertain due to measurement limits.

Digits 1–9 always count as significant. They represent measured information, not just placeholders.

In 3.40, the trailing zero is significant because it is explicitly written after the decimal. That indicates measured precision to the hundredths place.

Leading zeros are not significant; they only locate the decimal point. The digits 4, 5, and the final 0 are significant, giving 3 sig figs.

Leading zeros are placeholders. They don’t represent measured precision, only scale. Sig figs start at the first non-zero digit.

A zero inside the number (like 1002) is part of the measured value. It counts as a significant digit.

The two zeros are between 1 and 2, so they are significant. That makes 4 significant figures total.

Without a decimal point, trailing zeros may just be placeholders. So 1500 is usually taken as 2 sig figs unless specified otherwise.

The decimal shows the trailing zeros are measured, not placeholders. That makes 1500 have 4 sig figs.

1.50 × 10³ has three significant digits (1, 5, and 0). Scientific notation removes ambiguity about trailing zeros.

The power of 10 just sets scale. The coefficient’s digits determine precision.

In 2.030, the zero between 2 and 3 counts, and the final zero counts too because it’s after the decimal. That gives 4 sig figs.

Trailing decimal zeros indicate precision. They show the measurement was recorded to that place. So they count as significant.

Leading zeros don’t count, trailing decimal zeros do. The leading zeros are placeholders. The digits 3 and the final 0 are significant, giving 2 sig figs.

The decimal makes zeros significant. In 70.0, both zeros are significant because the decimal indicates measured precision to the tenths place. That’s 3 sig figs total.

Counted values are exact and don’t have measurement uncertainty in the same way. Sig figs matter for measurements with instrument limits.

Without a decimal, '500' typically implies 1 significant figure (the 5). The others explicitly show 3 significant figures.

Too many digits can imply accuracy you don’t really have. Sig figs help keep reported numbers honest.

Instruments give you certain digits, and you estimate one more digit beyond the smallest division. Sig figs capture that idea.

Significant figures encode precision in the recorded number. They help keep calculations consistent with the measurement limits.