Nearest Double Addition Strategy

What is a Nearest Double Addition Strategy?

A Nearest Double Addition Strategy is a math fact that is close to a doubles fact. For example, 6+7 is considered a near double because it is close to the doubles fact 6+6.

Near doubles could be doubles plus one facts, doubles plus two facts, or doubles minus one facts.

Let’s take a look at the doubles fact 5+5. 5+6 would be the double plus one (5+5 plus one more). 5+7 would be the double plus two (5+5 plus two more). 5+4 would be the double minus one (5+5 subtract one).

 

Nearest Double Addition Strategy Exploration Vs Menorization

The Nearest Double Addition Strategy  teaches us that we can make connections and form relationships between facts. However, we must be careful that we are not teaching this in a procedural way where our students “memorize” this strategy.

If you hear your students saying things like, “I can’t remember the Nearest Double Addition Strategy to use when the numbers are one apart!” or “I know I’m supposed to use the Nearest Double Addition Strategy for this problem, but I can’t remember how!” then they are not understanding this Nearest Double Addition Strategy in a conceptual way. Instead, they are trying to memorize it and apply it.

Ideally, we want to give our students the opportunity to explore this strategy and construct their own understanding. The best way to do this is through lots (and lots!) of time with manipulatives.

Teaching The Nearest Double Addition Strategy in a Conceptual Way

Take a look Nearest double addition strategy at this ten frame. The colors make it very easy to see 5+6 as 5+5 and then one more.

Here’s another example where we can see 3+5 as 3+3 and then two more.

We could also model near doubles on a Rekenrek. Here’s a representation of 5+6, which we can clearly see as 5+5 and then one more.

What are Doubles And Nearest Double Addition Strategy?

We explained this a bit, but let’s expand on these math definitions.

You might be thinking, “What!?” I have to admit, adding near doubles is a concept that I learned along with my oldest when she went through second grade.

What is Doubles and Nearest Double Addition Strategy in Second grade math?

Doubles are the addends that are exactly the same.  These are addition facts that second graders need to know to add within 20.

Near Doubles are those addends that are almost a double fact. So, 4+5 is very close to 4+4.  Students can easily recall that the double fact for 4+4=8 and by adding one more, they quickly know that 4+5=9.  These are math fact tools that can help second graders add within 20.

DOUBLES MATH FACTS

Doubles math facts include:

• 0+0=0
• 1+1=2
• 2=2+4
• 3+3=6
• 4+4=8
• 5+5=10
• 6+6=12
• 7+7=14
• 8+8=16
• 9+9=18
• 10+10=20

NEAR DOUBLES FACTS

Near doubles facts depend on the doubles that the numbers are near.

• 0+0=0
  • 1+0=1
  • 0+1=1
• 1+1=2
  • 2+1=3
  • 1+2=3
  • 0+1=1
  • 1+0=1

• 2+2=4
  • 3+2=5
  • 2+3=5
  • 1+2=3
  • 2+1=3
• 3+3=6
  • 4+3=7
  • 3+4=7
  • 2+3=5
  • 3+2=5
• 4+4=8
  • 5+4=9
  • 4+5=9
  • 3+4=7
  • 4+3=7
• 5+5=10
  • 6+5=11
  • 5+6=11
  • 4+5=9
  • 5+4=9
• 6+6=12
  • 7+6=13
  • 6+7=13
  • 5+6=11
  • 6+5=11
• 7+7=14
  • 8+7=15
  • 7+8=15
  • 6+7=13
  • 7+6=13
• 8+8=16
  • 9+8=17
  • 8+9=17
  • 7+8=15
  • 8+7=15
• 9+9=18
  • 10+9=19
  • 9+10=19
  • 8+9=17
  • 9+8=17
• 10+10=20
  • 11+10=21
  • 10+11=21
  • 9+10=19
  • 10+9=19

You can see how learning just a handful of doubles facts builds a bigger repertoire of math facts. This is a particularly good path strategy for learning tricky addition facts that kids often struggle with, especially with adding the higher 6’s, 7’s, 8’s, and 9’s.

Adding Doubles And Nearest Double Addition Strategy

Adding doubles is a math fact memorization technique.  It is easier for kids to remember that 2+2=4, 6+6=12, 7+7=14, 9+9=18, etc.

Kids can first memorize the doubles facts. Once they’ve got those addition facts down pat, recognizing that the near doubles facts are just one off from the double makes learning a whole new set of numbers easy.

For example:

First the student would memorize the near double of 6+6=12.

Then, when that becomes a math fact they know by sight, they can look at the math problem 6+5 and recognize that the addend 5 is just one less than the doubles fact for 6. They can know the number sense that the problem 6+5 is one less than 6+6 and easily identify the answer of 11.

Near doubles assist students with adding one more or one less than the doubles facts.

By this, we mean that once a student knows the doubles fact of 6+6=12, they then also know:

• 6+5=11
• 5+6=11
• 6+7=13
• 7+6=13

You can see how the doubles and near doubles concept builds number sense and allows students to become much more fluent and efficient at math problems.