Tens and Ones (Place Value)
Aligned to 1.NBT.B.2 — Common Core State Standards for Mathematics.
What this lesson teaches
Two-digit numbers are made of tens and ones. The first digit tells how many groups of ten; the second tells how many extra ones.
Worked example
The number 34 is 3 tens and 4 ones: 30 + 4 = 34.
Practice questions
- How many tens and ones are in 47?
- Build the number that is 5 tens and 2 ones.
- Which is bigger: 6 tens or 60 ones? Explain.
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
Decenas y unidades (valor posicional)
Los números de dos dígitos están formados por decenas y unidades. El primer dígito indica cuántos grupos de diez hay; el segundo indica cuántas unidades sueltas quedan.
Ejemplo: El número 34 tiene 3 decenas y 4 unidades: 30 + 4 = 34.
More Number & Operations in Base Ten lessons
Counting to 1201.NBT.A.1Which Is Bigger?1.NBT.B.3Adding Bigger Numbers1.NBT.C.410 More, 10 Less1.NBT.C.5Subtracting Tens1.NBT.C.6
Teach this lesson today
An AI tutor that guides with questions instead of just giving answers — all K–12 core subjects, every child in the family.
Start free — no card required