Examples of Doubles Plus One Addition

📚 Quick Study Guide

• ✅ Doubles Plus One Addition: This is when you add a number to itself, and then add one more. For example, $5 + 5 + 1$.
• ✅ The Pattern: Notice that $5+5+1$ is the same as $5 + 6$ or $6+5$. The 'plus one' essentially makes the second number one bigger than the first.
• ✅ Formula: We can write it like this: $n + n + 1 = n + (n+1)$
• ✅ Examples:
  • 2 + 2 + 1 = 5 (or 2 + 3 = 5)
  • 7 + 7 + 1 = 15 (or 7 + 8 = 15)
  • 9 + 9 + 1 = 19 (or 9 + 10 = 19)

✍️ Practice Quiz

1. Question 1: What is 4 + 4 + 1?
   1. 7
   2. 8
   3. 9
   4. 10
2. Question 2: Which of these is NOT an example of Doubles Plus One addition?
   1. 3 + 3 + 1
   2. 6 + 7
   3. 8 + 8
   4. 5 + 5 + 1
3. Question 3: What is the 'plus one' version of 6+6?
   1. 11
   2. 12
   3. 13
   4. 14
4. Question 4: What is 9 + 10 equal to, using the Doubles Plus One method?
   1. 9 + 9
   2. 9 + 9 + 1
   3. 10 + 10 + 1
   4. 10 + 10
5. Question 5: If you have 7 + 7 + 1 cookies, how many cookies do you have in total? 🍪
   1. 13
   2. 14
   3. 15
   4. 16
6. Question 6: Which of the following equations represents Doubles Plus One addition?
   1. $a + a = b$
   2. $a + b = c$
   3. $a + a + 1 = b$
   4. $a + 1 = b$
7. Question 7: If $x + x + 1 = 11$, what is the value of $x$?
   1. 4
   2. 5
   3. 6
   4. 7