Measurement

instrument -> decimal point -> accuracy, not s.n.
calculation -> significant figures -> the same as before

to avoid parallax(视差) error

reading need to be done at eye level
eye must be perpendicular to the scale
the bottom of the meniscus(液柱的弯月面)

Significant figures

Definition

All non-zero digits are significant: 1, 2, 3, 4, 5, 6, 7, 8, 9
Zeros between non-zero digits are significant: 102, 2005, 50009
Leading zeros are never significant: 0.02, 001.887, 0.000515.
In a number with a decimal point, trailing zeros (those to the right of the last non-zero digit) are significant: 389.000; 2.02000, 20.0000(all 6 s.f.)
In G-level, answer should always have 2 or 3 s.f.

Calculations

The result of a calculation should be expressed to the minimum number of significant figures used in the data for × and ÷ (or one more). (统一到有效数值最少数值)
For + and - give the answer to the fewest number of decimal places(d.p.) (统一到最不精确数值)

Drawing a Graph

Each large box(10 little boxes) should be a multiple of 1, 2, or 5.

Use at least half of the given space

Triangle must be shown clearly with no extra marks on the line

Pasted image 202408270956571. find two points(x1,y1), (x2,y2) and calculate it using the formula: $$ gradient=\frac{y2-y1}{x2-x1} $$
2. draw the tangent of the curve on that point and calculate the gradient of the line.
3. B is proportional to a
4. False

$4\times10^3$ four times ten to the (power of) three.
$1\mu g = 1\times 10^{-6}g$
$1ng = 1\times 10^{-9}g$