Lesson 20 Add and Subtract Within 1,000,000

  • Let’s use the standard algorithm to add and subtract.

Warm-up Notice and Wonder: Subtracting Tens of Thousands

What do you notice? What do you wonder?

Subtract. Seventy five thousand nine hundred forty, minus, twelve thousand seven hundred eighty six. 


Activity 1 Add and Subtract Large Numbers

Problem 1

Use the standard algorithm to find the value of each sum and difference. If you get stuck, try writing the numbers in expanded form.

Problem 2

Find the missing number that would make each computation true.

  1. add. sixty seven thousand, one hundred eighty two, plus, blank, equals, one hundred twenty nine thousand, four hundred.
  2. Subtract. Two hundred thirty four thousand, six hundred, fifty, minus, blank, equals, one hundred ninety three thousand, seven hundred, ten. 

Activity 2 Spot Errors

  1. Kiran is trying to find the sum of 204,500 and 695. He isn’t sure how to set up the calculation so he wrote down two ideas. Which way is correct? Be ready to share your thinking with your partner.

    add. two hundred and four thousand five hundred, plus, six in the hundred thousands place, nine in the ten thousands place, five in the thousands place, equals, eighty nine thousand, nine hundred fifty.
    add. Two hundred four thousand, five hundred, plus, six hundred ninety five, equals, two hundred five thousand, one hundred ninety five.
  2. Lin made some errors when subtracting 4,325 from 61,870. Identify as many errors as you can find. Then, show the correct way to subtract.

    subtract. sixty one thousand, eight hundred seventy, minus, four thousand, three hundred twenty five, equals, sixty six thousand, five hundred fifty five.

Practice Problem

Problem 1

Find the value of each sum and difference using the standard algorithm.