Virtual Instrument Reading Lab Test mode · Step 1 / 6

Area 1 MUST DO Option B  |  Measurement & Significant Figures  |  SC.912.N.1.1

Choose a mode:

Read each analog tool: read to the smallest division, then estimate ONE more digit. You need 1 correct reading per instrument, and the simulator moves you to the next one automatically.

  1. Look at the red indicator on the instrument and read its value.
  2. Type only the number in the box — do NOT type the unit (e.g. type 4.32, not 4.32 cm).
  3. Press Check (or press Enter). Your reading counts if it is correct.
  4. If it is not correct, press New reading to get a fresh value and try again.
  5. Once you get 1 correct reading, you automatically move to the next tool.

Tool 1 of 4 — Ruler

Length of the metal rod  |  smallest division 0.1 cm  |  read to 0.01 cm

Number only — no units. After checking, press “New reading” before the next reading.
Correct readings: ●●● 0 / 3

Tool 2 of 4 — Graduated Cylinder

Volume of water  |  read volume at the bottom of the liquid curve (meniscus)  |  smallest division 1 mL  |  read to 0.1 mL

Number only — no units. After checking, press “New reading” before the next reading.
Correct readings: ●●● 0 / 3

Tool 3 of 4 — Thermometer

Temperature of the liquid  |  read the top of the red liquid column  |  smallest division 1 °C  |  read to the nearest 0.1 °C

Number only — no units. After checking, press “New reading” before the next reading.
Correct readings: ●●● 0 / 3

Tool 4 of 4 — Triple-Beam Balance

Mass of the object  |  add the three beams; read the 1-gram beam to 0.01 g

Number only — no units. After checking, press “New reading” before the next reading.
Correct readings: ●●● 0 / 3

Part 2 — Why can we estimate one digit? (ruler & cylinder)

For an ANALOG tool like a ruler or graduated cylinder, the marks define the SMALLEST
DIVISION (e.g. 1 mm on a cm ruler). Because we can judge a fraction of the gap between
two marks by eye, we report ONE DIGIT PAST the smallest division -- the ESTIMATED
(uncertain) digit. That estimated digit tells a reader how precise the tool is, and
that the true value lies somewhere around it.

Example: a ruler with 0.1-cm marks can be read as 4.32 cm. The '3' is certain (it is a
0.1-cm mark); the '2' is the estimated digit (we judged 0.02 of the gap). Reporting
only '4.3' throws away real information; reporting '4.321' pretends to a precision
the tool cannot give.

DIGITAL tools differ: a digital display shows exactly the digits it can measure. You
NEVER add an estimated digit beyond the display -- the display has already done the
estimating for you.

Part 3 — Use your readings: metal rod density

Volume = length × width × thickness  •  Density = mass ÷ volume. Round your density to the correct number of significant figures (the ruler limits you to 0.01 cm).

Number only — no units.

Your readings

Only correct readings (per instrument) are recorded here.

InstrumentSmallest divCorrect readings recordedStatus