Detective Doubles Plus One!

Math Grades 1st Grade 6:58 Video
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Lesson Description

Become a math detective and learn to identify doubles plus one facts using a hundreds chart and blocks! We'll explore how numbers next to each other can help us add.

Video Resource

Grade 1: Math Lesson #77 Addition Facts - Identifying Doubles Plus One Facts

The Eagle's Nest - Our Online Classroom

Duration: 6:58
Watch on YouTube

Key Concepts

  • Doubles facts
  • Adding one more
  • Number relationships

Learning Objectives

  • Students will be able to identify doubles plus one facts.
  • Students will be able to solve doubles plus one addition problems.
  • Students will be able to explain how numbers next to each other on a number line relate to doubles plus one.

Educator Instructions

  • Introduction (5 mins)
    Begin by telling the class that they will be math detectives today. Show them a magnifying glass. Introduce the concept of 'doubles plus one' facts. Ask if anyone knows what a doubles fact is (e.g., 2+2, 3+3). Explain that a doubles plus one fact is when you add one more to a doubles fact (e.g., 2+3, 3+4).
  • Video Viewing (7 mins)
    Play the YouTube video: Grade 1: Math Lesson #77 Addition Facts - Identifying Doubles Plus One Facts. Encourage students to pay attention to how the teacher uses blocks and a hundreds chart to explain doubles plus one facts.
  • Discussion and Examples (8 mins)
    After the video, review what doubles plus one facts are. Use blocks or drawings to show examples like 4+5 or 6+7. Emphasize that the numbers are right next to each other on a number line or hundreds chart. Show examples that are NOT doubles plus one, such as 2+5, and explain why they don't fit the rule.
  • Practice Activity (10 mins)
    Give each student a worksheet with several addition problems. Some should be doubles plus one facts, and some should not. Have them circle the doubles plus one facts. For an extension, have them solve all the problems.

Interactive Exercises

  • Number Line Detective
    Draw a number line on the board. Call out different addition problems (e.g., 3+4, 5+6, 2+4). Have students point to the numbers on the number line and decide if it's a doubles plus one fact. If it is, they say "Detective Doubles!"
  • Block Building
    Provide students with blocks. Call out an addition problem (e.g., 4+5). Have them build towers with the blocks to represent the problem. Can they see the "doubles" part and the "plus one"?

Discussion Questions

  • What is a doubles fact?
  • How do you know if an addition problem is a doubles plus one fact?
  • Can you give me an example of a doubles plus one fact?

Skills Developed

  • Addition
  • Problem-solving
  • Number sense

Multiple Choice Questions

Question 1:

Which one is a doubles fact?

Correct Answer: 4 + 4

Question 2:

What is 3 + 3?

Correct Answer: 6

Question 3:

Which one is a doubles plus one fact?

Correct Answer: 3 + 4

Question 4:

What is 4 + 5?

Correct Answer: 9

Question 5:

If 6 + 6 = 12, what is 6 + 7?

Correct Answer: 13

Question 6:

Which numbers are next to each other on a number line?

Correct Answer: 4 and 5

Question 7:

If you know 5 + 5 = 10, how can you find 5 + 6?

Correct Answer: Add one more

Question 8:

Which of these is NOT a doubles plus one fact?

Correct Answer: 1 + 3

Question 9:

What is 2 + 3?

Correct Answer: 5

Question 10:

If you have 7 blocks and you add 8 more blocks, how many blocks do you have?

Correct Answer: 15

Fill in the Blank Questions

Question 1:

A doubles fact is when you add a number to _____.

Correct Answer: itself

Question 2:

3 + 4 is a doubles plus _____ fact.

Correct Answer: one

Question 3:

On a number line, numbers in a doubles plus one fact are next to each _____

Correct Answer: other

Question 4:

If 5 + 5 = 10, then 5 + 6 = _____.

Correct Answer: 11

Question 5:

Being a math detective means we _____ for doubles plus one facts!

Correct Answer: look

Question 6:

The numbers 6 and _____ are next to each other.

Correct Answer: 7

Question 7:

A doubles plus one fact is like a doubles fact plus _____ more.

Correct Answer: one

Question 8:

If you know 2 + 2, you can easily figure out 2 + _____.

Correct Answer: 3

Question 9:

7 + 8 is a doubles plus one fact because 7 + 7 is a _______ fact.

Correct Answer: doubles

Question 10:

4 + 3 is the same as 3 + _____

Correct Answer: 4

Educational Standards

CCSS.Math.Content.1.OA.C.6:Add and subtract within 20, demonstrating fluency for addition and subtraction within 10. Use strategies such as counting on; making ten (e.g., 8 + 6 = 8 + 2 + 4 = 10 + 4 = 14); decomposing a number leading to a ten (e.g., 13 - 4 = 13 - 3 - 1 = 10 - 1 = 9); using the relationship between addition and subtraction (e.g., knowing that 8 + 4 = 12, one knows 12 - 8 = 4); and creating equivalent but easier or known sums (e.g., adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13). CCSS.Math.Content.1.OA.B.3:Apply properties of operations as strategies to add and subtract. (Students need not use formal terms for these properties.) Examples: If 8 + 3 = 11 is known, then 3 + 8 = 11 is also known. (Commutative property of addition.) To add 2 + 6 + 4, the second two numbers can be added to make a ten, so 2 + 6 + 4 = 2 + 10 = 12. (Associative property of addition.) 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.

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