← Home

The multiples of 10

CONCEPTUAL
Mathematics›Number Representation & Place Value|Ages 6—7|ID: mt_zfy1gOEewd

Understand that the multiples of 10 (10, 20, 30 … 90) represent one to nine tens and 0 ones

Mastery Evidence

  • Explain that 30 means 3 tens and 0 ones
  • Represent 50 using 5 tens rods and no unit cubes
  • Match decade numbers to their tens representation

Assessment Prompt

“Can [child] explain that 60 means 6 tens and no ones — and that this is why the ones column has a zero as a placeholder?”

Curriculum Standards1 alignment

1.NBT.2.cCommon Core State Standards for Mathematics
Multiples of 10

The numbers 10, 20, 30, 40, 50, 60, 70, 80, 90 refer to one, two, three, four, five, six, seven, eight, or nine tens (and 0 ones).

NBT

Prerequisites2

Show full prerequisite tree
  • Counting in 2s soft

    Skip counting in tens supports recognising decade numbers

  • A Ten Is Ten Ones hard

    Understanding decade numbers as 'some tens and 0 ones' requires the concept of a ten

    • 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)

Unlocks1