Measuring with Two Different Units
Aligned to 2.MD.A.2 — Common Core State Standards for Mathematics.
What this lesson teaches
When you measure the same object with a smaller unit, you need more of them. A smaller unit gives a bigger number.
Worked examples
Example 1
A pencil is 6 inches long. Measured in centimeters it is about 15 cm. The centimeter is smaller, so the number is bigger.
Example 2
A table is 3 feet long, which is 36 inches. The inch is smaller, so it takes many more of them.
Example 3
Measuring your desk in centimeters gives a bigger number than measuring it in inches, even though the desk never changed size.
Practice questions
- A desk is measured in feet and in inches. Which unit gives the bigger number?
- If a rope is 2 feet long, is that more or fewer inches?
- Why do smaller units give bigger numbers for the same length?
Watch the lesson
Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.
▶ Watch this lessonEn español
Medir con dos unidades diferentes
Cuando mides el mismo objeto con una unidad más pequeña, necesitas más de ellas. Una unidad más pequeña da un número más grande.
Ejemplo 1: Un lápiz mide 6 pulgadas de largo. Medido en centímetros mide unos 15 cm. El centímetro es más pequeño, por eso el número es más grande.
Ejemplo 2: Una mesa mide 3 pies de largo, o sea 36 pulgadas. La pulgada es más pequeña, por eso se necesitan muchas más.
Ejemplo 3: Medir tu escritorio en centímetros da un número más grande que medirlo en pulgadas, aunque el escritorio nunca cambió de tamaño.
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