Adding Bigger Numbers
Aligned to 1.NBT.C.4 — Common Core State Standards for Mathematics.
What this lesson teaches
To add a two-digit number and a one-digit number, we can add the ones first, then put the tens back on.
Worked example
23 + 4. Add the ones: 3 + 4 = 7. Keep the 2 tens: the answer is 27.
Practice questions
- Add 42 + 5.
- Add 30 + 6.
- Add 51 + 8.
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
Sumar números más grandes
Para sumar un número de dos dígitos y uno de un dígito, podemos sumar las unidades primero y luego volver a poner las decenas.
Ejemplo: 23 + 4. Suma las unidades: 3 + 4 = 7. Guarda las 2 decenas: la respuesta es 27.
More Number & Operations in Base Ten lessons
Tens and Ones (Place Value)1.NBT.B.2Counting to 1201.NBT.A.1Which Is Bigger?1.NBT.B.310 More, 10 Less1.NBT.C.5Subtracting Tens1.NBT.C.6
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