Place Value, Rounding, and Multi-Digit Arithmetic
Aligned to 3.NBT.A.1 — Common Core State Standards for Mathematics.
What this lesson teaches
Rounding means finding the nearest ten or hundred so a number is easier to work with. Look at the digit just to the right of the place you are rounding to: if it is 5 or more, round up, otherwise round down. You can also add and subtract numbers up to 1000 by regrouping.
Worked example
Round 47 to the nearest ten. The ones digit is 7, which is 5 or more, so round up to 50.
Practice questions
- Round 62 to the nearest ten.
- Round 348 to the nearest hundred.
- What is 6 times 70?
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
Valor posicional, redondeo y aritmética con números de varios dígitos
Redondear significa encontrar la decena o centena más cercana para que un número sea más fácil de usar. Observa el dígito que está justo a la derecha del lugar al que estás redondeando: si es 5 o más, redondea hacia arriba; de lo contrario, redondea hacia abajo. También puedes sumar y restar números hasta 1000 usando reagrupación.
Ejemplo: Redondea 47 a la decena más cercana. El dígito de las unidades es 7, que es 5 o más, así que se redondea hacia arriba: 50.
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