Subscribe

2nd grade · Math · Unit 15 of 16

Add & Subtract to 1000

Hundreds, tens and ones

What your child practices

Adding and subtracting three-digit numbers using place value, and adding or taking away 10 or 100 in their head.

Alaska content standards learning standard: 2.NBT.7; 2.NBT.8 · adding and subtracting within 1000 using place value, and mentally adding or subtracting 10 or 100

How we explain it

Children can open this short lesson before they practice.

  1. Add the hundreds, then the tens, then the ones.
  2. Regroup 10 ones as a ten, or 10 tens as a hundred.
  3. 10 more or 100 more changes just one digit.

Example: What is 345 + 132? 300 + 100 = 400. 40 + 30 = 70. 5 + 2 = 7. 400 + 70 + 7 = 477. Answer: 477

Add & Subtract to 1000 in Alaska

In the Alaska content standards, this is unit 15 of 16 in 2nd grade Math, after Arrays and before Bar Graphs.

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: Alaska Department of Education and Early Development

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 959 − 486?

    959 − 486 = ?

    • 473
    • 483
    • 470
    • 463
    • 573

  2. Question 2

    350 + ? = 650. What number is missing?

    • 30
    • 300
    • 100
    • 310

  3. Question 3

    What is 10 more than 766?

    • 778
    • 767
    • 776
    • 866
    • 777

  4. Question 4

    What is 800 + 90 + 3?

    800 + 90 + 3 = ?

    • 20
    • 993
    • 893
    • 839

  5. Question 5

    What is 262 + 183?

    262 + 183 = ?

    • 455
    • 345
    • 545
    • 445
    • 435

  6. Question 6

    600 + ? = 700. What number is missing?

    • 10
    • 110
    • 200
    • 100

More 2nd grade