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1st grade · Math · Unit 1 of 16

Numbers to 20

Count, compare and build numbers

What your child practices

Counting, ordering and comparing numbers to 20, and seeing teen numbers as 1 ten and some ones.

New York State Learning Standards learning standard: NY-1.NBT.1 · counting, reading and writing numbers, and writing a number for a group of objects

How we explain it

Children can open this short lesson before they practice.

  1. Numbers 11 to 19 are 1 ten and some ones.
  2. Count on from 10: 11, 12, 13.
  3. The bigger number comes later when you count.

Example: How many tens and ones are in 17? 17 is 1 ten and 7 ones. 10 + 7 = 17. Answer: 1 ten and 7 ones

Numbers to 20 in New York

In the New York State Learning Standards, this is unit 1 of 16 in 1st grade Math, before Make 10.

Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.

Source: New York State Education Department (NYSED)

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    Build the number 20.

    Build it with tens rods and ones cubes.

  2. Question 2

    What number is missing?

    17, 18, , 20

    • 19
    • 18
    • 9

  3. Question 3

    Tap the numbers from smallest to biggest.

    • 5
    • 12
    • 15
    • 0

  4. Question 4

    How many 🍓?

    • 20
    • 10
    • 15

  5. Question 5

    Which number is bigger?

    • 7
    • 16

  6. Question 6

    How many 🎈?

    • 7
    • 16
    • 13

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