Name: counting significant figures in measurements
Uploaded: 2023-09-22T11:49:39.000Z
Duration: 1 min 44 s
Channel: JoVE

La certeza de la medición depende de dos factores: el número de dígitos de la medición y la precisión del instrumento utilizado.
En una cantidad medida, todos los dígitos, incluido el último dígito incierto, se denominan cifras significativas y se pueden determinar mediante reglas específicas.
Cualquier dígito distinto de cero y todos los ceros cautivos, que se encuentran entre dos dígitos distintos de cero, son significativos. Por ejemplo, 28 tiene dos cifras significativas, mientras que 26,25 tiene cuatro y 208 tiene tres.
Los ceros a la izquierda nunca son significativos, ya que solo ubican el punto decimal. Por ejemplo, 0,00208 tiene tres cifras significativas. Tales cantidades se pueden expresar usando notaciones exponenciales. Por lo tanto, 0,00208 se puede escribir como 2,08 × 10−3.
Los ceros finales solo son significativos en los números con formato decimal: 2200 tiene dos ceros finales y dos cifras significativas, mientras que 2200.0 y 2200.1 tienen 5 cifras significativas.
En el caso de las cantidades sin decimales, el significado de los ceros finales se vuelve ambiguo. Por lo tanto, 2200 se puede escribir como 2,2 × 103 con dos cifras significativas o 2,20 x 103 con tres cifras significativas.

reglas de las figuras significativas

Rules of Significant Figures

En cualquier medición, la precisión de la herramienta de medición es un factor esencial. Por ejemplo, una regla ordinaria puede medir la longitud hasta el milímetro más cercano; por otro lado, un calibrador puede medir la longitud hasta el centésimo de milímetro más cercano. Como resultado, el calibrador es una herramienta de medición más precisa porque puede medir cambios extremadamente pequeños en la longitud. Las mediciones serán más exactas si la herramienta de medición es más precisa. Se debe enfatizar que cuando representamos valores medidos, la última cifra ha sido calculada de alguna manera por la persona que realiza la medición. Por ejemplo, una persona que mide la longitud de un palo con una regla nota que parece estar entre 13,2 cm y 13,3 cm, por lo que debe estimar el valor de la última cifra. La regla de las cifras significativas establece que la última cifra registrada en una medición es la primera cifra con cierta incertidumbre. Comienza con el primer valor medido a la izquierda y cuenta el número de cifras hasta la última cifra escrita a la derecha para determinar el número de cifras significativas en un valor. Las cifras significativas representan la precisión de la herramienta de medición utilizada para medir un valor. El texto es adoptado de <a href="https://openstax.org/books/university-physics-volume-1/pages/1-6-significant-figures">Openstax, University Physics Volume 1, Section: 1.6 Significant Figures. </a>

Reglas de las Figuras Significativas

En cualquier medición, la precisión de la herramienta de medición es un factor esencial. Una regla ordinaria, por ejemplo, puede medir la longitud ...

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counting significant figures in measurements

Significant figures help students record measurements with the correct level of precision. They show which digits in a number are meaningful and which only help place the decimal point. In science class, this idea matters when writing and comparing measured values.

The rules for significant figures explain how to count these digits in different numbers. Some digits are always counted, while others depend on where they appear in the number. Learning the rules makes it easier to report answers clearly and consistently.

This topic is especially useful in physics and other measurement-based science work. It helps students decide how many digits to keep when writing results from lab work or calculations. That makes numerical answers easier to interpret and compare.

Counting Significant Figures in Measurements

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Significant figures help students record measurements with the correct level of precision. They show which digits in a number are meaningful and which only help place the decimal point. In science class, this idea matters when writing and comparing measured values. The rules for significant figures explain how to count these digits in different numbers. Some digits are always counted, while others depend on where they appear in the number. Learning the rules makes it easier to report answers...

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Learn how to count significant figures in measurements and report scientific values with the right precision for high school science and lab work.

Counting Significant Figures in Measurements | JoVE K12

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Counting Significant Figures in Measurements

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