There is a ruler with a length of 9 cm but no scales, can you draw three tick marks on it?

This question can refer to the renminbi, which has three denominations of the same unit.

Draw a 2 cm scale at one end of the ruler, then a 5 cm scale from this end, and then a 1 cm scale from the other end. This makes it possible to measure all whole centimeters of length of 1 9 cm directly.

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Solution: If you want to measure 8 cm at a time, you must set a tick mark at 1 cm or 8 cm These two positions are symmetrical, and the first tick mark must be selected at 1 cm.

After the first scale is decided, in order to measure 7 cm at a time, another scale must be set in one of the following three places: 2 cm (difference 9-2 = 7); 7 cm (7-0=7); 8 cm (8-1=7) However, if you choose 8 cm, there will be two pairs of the same difference: 8-0 = 9-1, 9-8 = 1-0 So the second scale cannot be selected at 8 cm

Assuming that the second scale is selected at 2 cm, in order to measure 6 cm at a time, one of the following 4 scales must be set: 3 cm (9-3=6); 6 cm (6-0=6); 7 cm (7-1=6); 8 cm (8-2 = 6) But at 3, 7, and 8, there will be two pairs of the same difference, so the third scale can only be set at 6 cm

Unless it's a paper ruler, fold the paper ruler into three proportional sections, and then draw three lines one centimeter apart on the three folded sections.

Solution: It can directly measure six lengths; They are 1 cm, 2 cm, 3 cm, 5 cm, 6 cm, 8 cm. So the answer is: six; 1 cm, 2 cm, 3 cm, 5 cm, 6 cm, 8 cm.

Analysis: One length = last scale Previous scale.

Ruler scale: The scale of the ruler is the starting point of the scale of the tool (such as a ruler, tape measure) and the line segment to measure the length. Measure length tool, tick mark with zero line segment scale. Using a measuring tool with a zero tick mark will be easier to read and use.

The graduation value of the scale is generally 1mm, and the student range of the general specification is 10cm, 15cm, and 20cm. Measuring length with a scale is a fundamental skill in physical experiments, and it is also the basis for correct readings from other measuring instruments.

A mark should be made at cm, i.e. any integer centimeter between 1 and 11 cm in length.

0 to 1 1 cm ; 1 to 3 2 cm; 0 to 3 3 cm; 3 to 7, 4 cm; 0 to 1 + 3 to 7 5 cm; 1 to 7 6 cm; 0 to 7 7 cm; 3 to 11 8 cm; 1 to 11 is 10 cm; total length 11 cm; The difference of 9 centimeters is a size, which is 8 centimeters plus 1 centimeter.

Three scales should be engraved to ensure that any integer scale from 1 to 11 is measured at once without any marking. 3 and 4 measure 1 cm, 9 and 11 measure 2 cm, 3 cm, 4 cm, 4 and 9 measure 5 cm, 3 and 9 measure 6 cm, 4 and 11 measure 7 cm, 3 and 11 measure 8 cm, 9 cm, and then the key point comes: the measured length is between 9 and 11 cm, because it is an integer scale, so it must be 10 cm.

Then 11 cm. The main point of thinking is that the four numbers composed of the three scales and 11 should be different from each other and not the same as the number of the scale.

The common answer given by others is, I don't understand how to measure 10 centimeters at one time? Is it 2 and then 8? If this could be done, wouldn't it be possible to measure all the scales with just one tick 1?

This ruler can directly measure which 8 different lengths of line segments, which are 1 cm, 2 cm, 4 cm, 10 cm, 6 cm, 3 cm, 9 cm, and 8 cm.

You can directly measure the length of the line segment:

1-0=1 (cm).

2-0=2 (cm).

4-0=4 (cm).

10-0=10 (cm).

10-4 = 6 (cm).

4-1 = 3 (cm).

10-1 = 9 (cm).

10-2 = 8 (cm).

Answer: This ruler can directly measure which 8 different lengths of line segments, which are 1 cm, 2 cm, 4 cm, 10 cm, 6 cm, 3 cm, 9 cm, and 8 cm.

Summary. Analysis: There are scales in 1 cm, 4 cm, and 9 cm, indicating that it can accurately measure 1 cm, 4 cm, and 9 cm at one time, and then measure these accurate lengths according to 4-1 = 3 cm, 9-1 = 8 cm, and 9-4 = 5 cm.

An incomplete ruler only"1 cm","4 cm","9 cm"There are scales in three places, and there is the length that can be measured at one time with this ruler.

Hello, glad to answer for you! I am Teacher Luomeng Your question I have seen the spring slow ruler, and now I am sorting out the answer, it will take about three minutes, please wait a while If my answer is helpful to you, please give it a thumbs up, thank you

There are 9 types of lengths that can be measured at one time with this ruler. They are: 1 cm, 3 cm, 4 cm, 5 cm, 8 cm, 9 cm.

Analysis: 1 cm, 4 cm, 9 cm three places have engraved circle simplicity, indicating that it can accurately measure 1 cm, 4 cm, 9 cm at one time, and then according to 4-1 = 3 cm, 9-1 = 8 cm, 9-4 = 5 cm, measure the exact length of this cavity and several quasi-late pants.

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It can measure 3 cm, 5 cm, 8 cm.

The ruler below has 4 scales, which lengths can be directly measured with it?

There are only 4 scales left in the ruler below, and what lengths can be used to make it.

You can hold the shirt to draw a stuffy cavity29, cover God59