Rulers have long been made from different materials and in a wide range of sizes. Some are wooden. Plastics have also been used since they were invented; they can be molded with length markings instead of being scribed. Metal is used for more durable rulers for use in the workshop; sometimes a metal edge is embedded into a wooden desk ruler to preserve the edge when used for straight-line cutting.
In the history of measurement many distance units have been used which were based on human body parts such as the cubit, hand and foot and these units varied in length by era and location.[4] In t
Rulers have long been made from different materials and in a wide range of sizes. Some are wooden. Plastics have also been used since they were invented; they can be molded with length markings instead of being scribed. Metal is used for more durable rulers for use in the workshop; sometimes a metal edge is embedded into a wooden desk ruler to preserve the edge when used for straight-line cutting.
In the history of measurement many distance units have been used which were based on human body parts such as the cubit, hand and foot and these units varied in length by era and location.[4] In the late 18th century the metric system came into use and has been adapted to varying degrees in almost all countries in the world. The oldest preserved measuring rod is a copper-alloy bar that dates from c. 2650 BCE and was found by the German AssyriologistEckhard Unger while excavating at Nippur. Rulers made of Ivory were in use by the Indus Valley Civilization period prior to 1500 BCE. Excavations at Lothal (2400 BCE) have yielded one such ruler calibrated to about 1â16 inch (1.6 mm). Ian Whitelaw holds that the Mohenjo-Daro ruler is divided into units corresponding to 1.32 inches (33.5 mm) and these are marked out in decimal subdivisions with amazing accuracy, to within 0.005 inches (0.13 mm). Ancient bricks found throughout the region have dimensions that correspond to these units.
Anton Ullrich invented the folding ruler in 1851. Frank Hunt later made the flexible ruler in 1902.
The equivalent of a ruler for drawing or reproducing a smooth curve, where it takes the form of a rigid template, is known as a French curve. A flexible device which can be bent to the desired shape is known as a flat spline, or (in its more modern incarnation) a flexible curve. Historically, a flexible lead rule used by masons that could be bent to the curves of a molding was known as a lesbian rule.
Ruler - MEASURE LENGTH provides rulers and angle measures in your mobile. Portable Ruler app includes the following function Calculation of the length, Straight line, Angle Measure as Protector.
Calibration can be done by measuring the specific length of line.
Ruler - is beautiful, functional and easy to use tool on every smartphone or tablet.
Screen ruler has scale, multiple units of length (centimetre, meter, inch) used to measure the distance.
Features:
- Accuracy of measurement
- Easy to use
- User Friendly design
- Multiple units: cm, mm, inch
- measurement of the length either side of the device
- Variable calibration
OVERVIEW:
Ruler - MEASURE LENGTH is a free educational mobile app By Keyur Developers.It helps students in grades 2 practice the following standards 2.MD.A.2.
This page not only allows students and teachers download Ruler - MEASURE LENGTH but also find engaging Sample Questions, Videos, Pins, Worksheets, Books related to the following topics.
1. 2.MD.A.2 : Measure the length of an object twice, using length units of different lengths for the two measurements; describe how the two measurements relate to the size of the unit chosen..
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