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The two digits of a two-digit number

CONCEPTUAL
Mathematics›Number Representation & Place Value|Ages 6—7|ID: mt_THl9GLxwoL

Understand that the two digits of a two-digit number represent amounts of tens and ones

Mastery Evidence

  • Explain that in 47, the 4 represents 4 tens (40) and the 7 represents 7 ones
  • Use base-ten blocks to show a two-digit number as tens and ones
  • Identify the tens digit and ones digit in any two-digit number

Assessment Prompt

“If [child] sees the number 47, can they tell you there are 4 tens (forty) and 7 ones — rather than just reading the digits as 'four seven'?”

Curriculum Standards2 alignments

1.NBT.2Common Core State Standards for Mathematics
Understand place value of two-digit numbers

Understand that the two digits of a two-digit number represent amounts of tens and ones. Understand the following as special cases:

NBT
Maths/Y2/NPV/2The national curriculum in England
Recognise place value

Recognise the place value of each digit in a two-digit number (tens, ones).

Mathematics · Key Stage 1

Prerequisites2

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  • A Ten Is Ten Ones hard

    Understanding tens and ones place value requires the concept of 10 as a bundle

    • The teen numbers hard

      Understanding 10 as a bundle builds on understanding teen numbers as 'a ten and some ones'

      • How Many in Total? hard

        Understanding tens-and-ones composition requires cardinality — knowing numbers represent quantities

        • One-to-one counting hard

          Cardinality principle builds on one-to-one correspondence — you must count correctly to know the last number tells 'how many'

      • Reading and writing numbers to 20 hard

        Composing/decomposing teen numbers requires reading and writing those numerals

        • How Many in Total? hard

          Reading/writing numerals 0–20 requires understanding that numerals represent quantities (cardinality)

          • One-to-one counting hard

            Cardinality principle builds on one-to-one correspondence — you must count correctly to know the last number tells 'how many'

        • Writing digits 0-9 hard

          Writing numerals requires the motor skill of forming digits 0-9 (taught in English handwriting)

  • The teen numbers hard

    General two-digit place value extends from understanding teen number composition

    • How Many in Total? hard

      Understanding tens-and-ones composition requires cardinality — knowing numbers represent quantities

      • One-to-one counting hard

        Cardinality principle builds on one-to-one correspondence — you must count correctly to know the last number tells 'how many'

    • Reading and writing numbers to 20 hard

      Composing/decomposing teen numbers requires reading and writing those numerals

      • How Many in Total? hard

        Reading/writing numerals 0–20 requires understanding that numerals represent quantities (cardinality)

        • One-to-one counting hard

          Cardinality principle builds on one-to-one correspondence — you must count correctly to know the last number tells 'how many'

      • Writing digits 0-9 hard

        Writing numerals requires the motor skill of forming digits 0-9 (taught in English handwriting)

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