Estimating Lengths

Aligned to 2.MD.A.3 — Common Core State Standards for Mathematics.

What this lesson teaches

An estimate is a smart guess about how long something is. Compare the object to a unit you know, like your finger or your foot.

Example 1

Your finger is about 1 inch wide. A crayon is about as long as 3 fingers, so it is about 3 inches long.

Example 2

A doorway is about as tall as you plus half of you again, so about 7 feet. That is an estimate, not a measurement.

Example 3

Estimate the length of your bed in meters: a big step is about 1 meter, so if it takes 2 big steps, the bed is about 2 meters.

Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.

Una estimación es una suposición inteligente de cuánto mide algo. Compara el objeto con una unidad que conoces, como tu dedo o tu pie.

Ejemplo 1: Tu dedo mide como 1 pulgada de ancho. Un crayón mide como 3 dedos de largo, entonces mide como 3 pulgadas.

Ejemplo 2: Una puerta mide más o menos tu altura y media, o sea como 7 pies. Eso es una estimación, no una medida.

Ejemplo 3: Estima el largo de tu cama en metros: un paso grande mide como 1 metro, así que si toma 2 pasos grandes, la cama mide como 2 metros.

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