Sig. Figs. 2

Significant Figures 2.0

🧪 INSTRUCTIONS:

1) Take notes on Sig. Figs. Quick Examples below
2) Then Complete the Significant Figures 2 assignment (below)
3) Screenshot your name + score to the Google Classroom when finish

Significant Figures (Addition and Subtraction)

Notebook Rule

Add/Subtract → round by decimal places, not total sig figs.
Your final answer must have the same number of decimal places as the measurement with the fewest decimal places.

Line up the decimals.
Do the addition or subtraction.
Identify the fewest decimal places among the original numbers.
Round the result to that many decimal places.

Tip: Trailing zeros after a decimal (e.g., 12.30) show precision and count toward decimal places for this rule.

Quick Examples

1) 12.30 g + 0.455 g + 3.2 g

12.30 + 0.455 + 3.2 ──────── 15.955 (raw total)

Fewest decimal places among data = 1 (because of 3.2).

Round 15.955 to 1 decimal place → 16.0 g

2) 18.5 mL − 2.43 mL

18.5 − 2.43 ─────── 16.07 (raw difference)

Fewest decimal places = 1 (because of 18.5).

Round 16.07 to 1 decimal place → 16.1 mL

3) 7.00 cm + 3.456 cm + 12 cm

7.00 + 3.456 + 12 ──────── 22.456 (raw total)

Fewest decimal places = 0 (because of 12 has no decimal places).

Round 22.456 to 0 decimal places → 22 cm

4) 150.0 g − 0.260 g

150.0 − 0.260 ──────── 149.740 (raw difference)

Fewest decimal places = 1 (because of 150.0).

Round 149.740 to 1 decimal place → 149.7 g

5) 120.0 m + 0.8 m + 4 m

120.0 + 0.8 + 4 ────── 124.8 (raw total)

Fewest decimal places = 0 (because of 4).

Round 124.8 to 0 decimal places → 125 m

Why this matters: Addition/subtraction propagate decimal-place certainty. Multiplication/division use total sig figs instead (different rule).

Significant Figures 2

First name

Student number

Student: Score (after Q25): --

Question text.

Assignment Complete

Student:

Score ID:

Screenshot Demo Click here for Screenshot