What s a good way to estimate the length or width of something?

To estimate the length and width of things, we first need to learn the following steps. It will reduce the error of this kind of thing.

1) Recognition is to recognize the scale. First, observe whether its zero tick line is worn out. Second, observe its range and graduation value.

If the zero mark is worn, its zero mark can no longer be used as the starting point of measurement, and then any tick mark can be selected on the scale as the starting point of measurement. The smaller the graduation value, the higher the accuracy. The degree of accuracy that can be achieved in the measurement is determined by the graduation value of the scale.

2) put, that is, the position of the ruler should be corrected. The first is to align the zero line of the scale with the edge of the object to be measured; Second, the scale should be parallel to the edge of the object to be measured, that is, along the length to be measured; Third, for thicker scales, the scale marks should be close to the measured object.

3) Look, that is, the line of sight should not be skewed, and the line of sight should be perpendicular to the ulnar surface.

4) Reading, that is, reading, in addition to reading out the accurate value above the graduation value, but also to estimate the next digit of the reading value (estimated value).

5) Record the measurement results should include accurate values, estimates and units. Friendly reminder: If you don't have a given scale in advance, you should also choose the appropriate scale according to the requirements of the measurement. Units and conversions of time.

When using a scale to measure physical length, the following points should be generally noted:

1) See if the zero mark of the scale is worn. If it has been worn, it should be measured from other clear lines;

2) Look at the measuring range (measurement range) of the scale. In principle, the length measurement requires a measurement, if the measurement range is less than the actual length, it is necessary to move the scale to measure several times, which will produce a large error;

3) Look at the graduation value of the scale. The index value reflects the accuracy of the scale and the validity of the measurement. The range and indexing value should be selected according to the requirements of the actual measurement;

4) The key to correct placement is to do: the lower edge of the object is aligned with the foot test, and the coincidental foot without the skewed aspect must keep up with the object to be measured, and it cannot be "suspended";

5) When reading, the line of sight should be perpendicular to the ruler surface, and do not squint.

If you want to accurately estimate the length and width of a thing, he has no good way, you must usually practice more against a one-meter thing, it will leave a deep impression in your mind, you can also use your fingers to measure in a blink of a blink, or use your steps to measure, generally speaking, the normal step is 75 cm, so the estimated value should be about the same.