Subscribe

2nd grade · Math · Unit 2 of 16

Facts to 20

Add and take away

What your child practices

Fluent facts to 20 using strategies like making ten and thinking addition to subtract.

Arizona Academic Standards learning standard: 2.OA.B.2 · fluently adding and subtracting within 20

How we explain it

Children can open this short lesson before they practice.

  1. Use 10 as a stepping stone.
  2. Break one number to make a 10 with the other.
  3. Then add what is left over.

Example: 8 + 5 = ? 8 needs 2 more to make 10. Take 2 from 5. That leaves 3. 10 + 3 = 13. Answer: 13

Facts to 20 in Arizona

In the Arizona Academic Standards, this is unit 2 of 16 in 2nd grade Math, after Bigger or Smaller and before Adding to 100.

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: Arizona Department of Education

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

    What is 18 − 7?

    18 − 7 = ?

    • 5
    • 16
    • 11

  2. Question 2

    What is 5 + 9?

    • 14
    • 19
    • 13

  3. Question 3

    What is 16 − 5?

    16 − 5 = ?

    • 9
    • 11
    • 15

  4. Question 4

    What number is missing?

    6 + = 16

    • 5
    • 10
    • 4

  5. Question 5

    What is 10 − 4?

    10 − 4 = ?

    • 3
    • 7
    • 6

  6. Question 6

    What is 9 + 7?

    9 + 7 = ?

    • 11
    • 16
    • 20

More 2nd grade