JPS6017003Y2 - Slide rule for adding and subtracting fractions with equal denominators - Google Patents

Description

[Detailed explanation of the invention] This invention is mainly related to a slide rule for adding and subtracting fractions with the same denominators, which is used by students in lower grades.The purpose is to have a very simple structure, but it is possible to add and subtract fractions with the same denominators by color matching. It is an object of the present invention to provide a slide rule that is devised so that the operation of adjoining cylinders and adjusting the scale can be easily and easily understood.

Hereinafter, one embodiment of this invention will be described in detail with reference to the drawings. This slide rule consists of two square cylinders A and B (the cylinders are The cross-sectional size is 2 cm square), and the four outer surfaces of both cylindrical bodies A and B are lined with a center line 9 in the length direction.
Divide into two by 9ro and H2 and each have 8 belt surfaces a□~a8.
bi to b8, and the first band surface a1. In b□, '0. l/
2. 1. 11/2.2. ...4J is displayed, and the second band surface a2. b2 is '0,1/3°2/3.' as the second kind of same denominator fraction scale P2 containing integers. 1. 1
1/3...4J is displayed, and the third band surface a3*
b3 is '0.1/4.2/4.3/4.1 as the third kind of same denominator fraction scale P3 including integers. 11/4...
...Display 4yo, and the fourth obi surface a4? b4 is '0.115 as the fourth kind of same denominator fraction scale P4 that includes integers.
．． 215.315, 415. 1. 1115...
...4J is displayed, and the fifth type of homodenominator fraction scale P5, which includes integers, is '0.1/6.2/' on the fifth band surface mo and b5.
6.3/6t 4/6.5/6. 1゜11/6-...
...Display 4yo, the 6th type obi surface 4. b6 is '0.1/8.2 as the 6th kind denominator fraction scale P6 including integers.
/8.3/8...4J is displayed, and the seventh and eighth band surfaces a7. b7 and a8. bB contains the integer 7th
Same denominator fraction scale of species and 8th species P7. '0 as P8.
1/9.2/9.3/9---4. “0”
1/10.2/10, 3/10.4/10...
4J is displayed.

In addition, the same denominator fraction scales P1 to P of the 1st type to 8th type
3 is the left end side of the cylinders A and B (in the example, 7rI from the end face)
Set the 0-point scale at the position rIIt away) and turn the cylinder body A.
, the final scale on the right side of B (the scale of r4 in the example)
Together, they are displayed as a fractional division scale of the same length L (2200 in this example), with each scale indicating line P' positioned at the corner of the cylinder so that the ridges can be aligned. There is.

Also cylinder A. Each band surface a1 to a3 of B. For example, to b1~, the first band surface a□, b1 is red, the second band surface is brown, b2 is blue, the third band surface a3. b3 is yellow, fourth band surface a49
b is colored in eight different colors, such as green, etc., and the first type fractional scales P1 to P of both cylinders A and B are
1 comrade 1, second type fraction scale P2 ~ P2 comrade...
- Type 8 fractional scales P8 to P8 can be placed adjacent to each other with matching colors.

Next, how to use the slide rule constructed as described above will be explained.

(1) When adding the same denominator fractions For example, when calculating 1/2 + 1172, place two cylinders A and B adjacent so that the band surfaces a□ and b1 match,
Shift both cylinders A and B as shown in Figure 3, and place the rOJ scale on the same denominator fraction scale P on the other cylinder B at the 1112J position on the same denominator fraction scale P□ on one cylinder A. Combine,
In this state, at the scale position rl 1/2 on the cylinder B side, it is sufficient to read the scale of r2J on the cylinder body A side, which matches this position.

Note that when the cylinders A and B are aligned as shown in Fig. 3, the same denominator fraction scale P1. P1 matches with a difference of 1112 yo, so 1/2+1/2. I/21.
1/2+11/2. 1/2+2. 1/2+21/
2. ]/2+3.172+3172 can be similarly performed without moving cylinders A and B.

(2) When subtracting the same denominator fractions For example, when calculating 11/2-172, place the two cylinders A and B adjacent so that the band surfaces a□ and b1 match,
Both cylindrical bodies A and B are shifted as shown in Fig. 4, and one cylindrical body A is 11/2. '1/ of the other cylindrical body B at the scale position of
Align the scale at 2 yo, and in this state, set the 10 yo scale on the cylinder body B side. At the scale position, read the scale 71J on the cylinder A side that matches this scale.

Note that the addition and subtraction described in (1) and (2) above are examples when the fraction denominator is r2 yo, and the fraction denominator is 3, 4.
J, 5. 6. Addition and subtraction of the same denominator fractions of 8J, 9yo, and 10J can be performed in exactly the same manner as in (1) and (2> above.

The slide rule of this invention is as described above, so although it has a very simple structure with two square cylinders A and B, addition and subtraction of the same denominator fractions can be done by matching the colors of adjacent cylinders. This has the advantage that the scale adjustment operation is simple and easy to understand.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of this invention, and Fig. 2 is a perspective view showing an embodiment of the invention.
The developed plan view of the book cylinder, FIGS. 3 and 4 are explanatory diagrams of the state of use. A, B...Cylinder, I99, Honey...
・Central line, a1 to a8. b1 to b8...Band surface,
P1 to P8...The 1st to 8th type homogeneous denominator fraction scale.

Claims (1)

[Scope of utility model registration request] It is equipped with two regular rectangular cylinders of the same length and size set to an appropriate length, and the four outer surfaces of both cylinders A and B are aligned with the center line A99 and H2 in the length direction. divided into eight band surfaces a1 to a8. b1 to b8, and both cylinders A,
Each band surface a□ to a8 of B. b □ ~ The same denominator fraction scales P1 to P8 of the 1st type to 8th type containing integers are aligned with the 0 point scale on the left end side of the cylinders A and B, respectively, and the cylinders A and B are
The final scale is aligned on the right end side and displayed as a divided scale corresponding to fractions of the same length, and the first type fractional scales P1 to P1 of both cylinders A and B, and the second type fractional scales P2 to P1.
2 comrades... Fraction-corresponding band surfaces a1. A slide rule for adding and subtracting the same denominator fractions, which is colored in 8 colors from b□ to a8 to b8.