In measurement how many digits of estimation do you add at the end
1

Zeros in end count if
there is decimal point

Add +/- what
half of tick unit

+/- what for electronic balance if it goes to two decimal places (e.g. 1.26 grams)
0.01

In addition take lowest what
precision

In multiplication/division take lowest what
significant figure count

Precision means
distance from other results

Accuracy means
distance from real value

High precision, low accuracy means?
systematic error