Adding Big Numbers: Hundreds, Tens, and Ones!

Math Grades 1st Grade 3:36 Video
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Lesson Description

Let's learn how to add big numbers by adding the ones, then the tens, and then the hundreds! We'll use blocks to help us see how it works.

Video Resource

Adding hundreds, tens, and ones | Addition and subtraction within 100 | Early Math | Khan Academy

Khan Academy

Duration: 3:36
Watch on YouTube

Key Concepts

  • Place Value (Hundreds, Tens, Ones)
  • Addition
  • Breaking down numbers into hundreds, tens, and ones

Learning Objectives

  • Students will be able to identify the hundreds, tens, and ones in a three-digit number.
  • Students will be able to add two three-digit numbers by adding the ones, then the tens, and then the hundreds.

Educator Instructions

  • Introduction (5 mins)
    Start by reviewing what hundreds, tens, and ones are. Ask students to give examples of numbers that have different amounts of hundreds, tens and ones (e.g., What number has 2 hundreds, 3 tens, and 5 ones?).
  • Watch the Video (7 mins)
    Play the Khan Academy video "Adding hundreds, tens, and ones | Addition and subtraction within 100 | Early Math | Khan Academy". Encourage students to pay attention to how the speaker breaks down the numbers into hundreds, tens, and ones and how they add the parts together.
  • Guided Practice (10 mins)
    Work through a couple of example problems together as a class. Use drawings of squares, lines, and dots to represent hundreds, tens, and ones, just like in the video. For example: 231 + 145 = ? Draw 2 squares, 3 lines, and 1 dot for 231. Draw 1 square, 4 lines, and 5 dots for 145. Add the dots (1+5=6), add the lines (3+4=7), and add the squares (2+1=3). The answer is 376.
  • Independent Practice (10 mins)
    Give students a worksheet with several addition problems involving three-digit numbers. Encourage them to use the drawing strategy to solve the problems. Provide assistance as needed.
  • Wrap-up (3 mins)
    Review the key concepts of the lesson. Ask students to explain in their own words how to add three-digit numbers by adding the ones, then the tens, and then the hundreds.

Interactive Exercises

  • Place Value Game
    Use base-ten blocks (hundreds flats, tens rods, and ones units) to represent numbers. Have students build numbers and then add them together. This provides a hands-on experience to reinforce place value concepts.
  • Online Addition Game
    Use an interactive online game focusing on adding numbers within 1000. This gamified approach will help students practice the concepts in a fun way.

Discussion Questions

  • What is the biggest number you can have in the ones place?
  • Why do we add the ones first, then the tens, then the hundreds?
  • Can you think of a time when you might need to add big numbers like this in real life?

Skills Developed

  • Place Value Understanding
  • Addition Skills
  • Problem-Solving

Multiple Choice Questions

Question 1:

What number is in the HUNDREDS place in 325?

Correct Answer: 3

Question 2:

What number is in the TENS place in 182?

Correct Answer: 8

Question 3:

What number is in the ONES place in 459?

Correct Answer: 9

Question 4:

What is 100 + 200?

Correct Answer: 300

Question 5:

What is 30 + 40?

Correct Answer: 70

Question 6:

What is 2 + 5?

Correct Answer: 7

Question 7:

If you have 2 hundreds, 1 ten, and 3 ones, what number do you have?

Correct Answer: 213

Question 8:

If you have 1 hundred, 4 tens, and 0 ones, what number do you have?

Correct Answer: 140

Question 9:

321 + 100 = ?

Correct Answer: 421

Question 10:

156 + 10 = ?

Correct Answer: 166

Fill in the Blank Questions

Question 1:

The number 245 has ___ hundreds.

Correct Answer: 2

Question 2:

The number 183 has ___ tens.

Correct Answer: 8

Question 3:

The number 309 has ___ ones.

Correct Answer: 9

Question 4:

100 + 100 = ____

Correct Answer: 200

Question 5:

20 + 30 = ____

Correct Answer: 50

Question 6:

4 + 1 = ____

Correct Answer: 5

Question 7:

In the number 467, the 6 is in the ____ place.

Correct Answer: tens

Question 8:

In the number 921, the 9 is in the ____ place.

Correct Answer: hundreds

Question 9:

200 + 10 + 5 = ____

Correct Answer: 215

Question 10:

100 + 30 + 2 = ____

Correct Answer: 132

Educational Standards

1.NBT.C.4:Add within 100, including adding a two-digit number and a one-digit number, and adding a two-digit number and a multiple of 10, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used. Understand that in adding two-digit numbers, one adds tens and tens, ones and ones; and sometimes it is necessary to compose a ten. 1.NBT.B.2:Understand that the two digits of a two-digit number represent amounts of tens and ones. Understand the following as special cases: CCSS.Math.Content.1.OA.A.1:Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using objects, drawings, and equations with a symbol for the unknown number to represent the problem.

Teaching Materials

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