Grade 1Adding and Subtracting within 201.OA.C.6

Doubles and Near Doubles

6 + 7 is 6 + 6 and one more.

Since you can add in any order, you can use facts you know to find new ones. Doubles are two of the same, like $6 + 6$.

$6 + 7$: a double 6, plus 1 more yellow counter.

Key idea

A near double is a double plus one: $6 + 7 = 6 + 6 + 1 = 13$.

Why it works

7 is 6 and 1 more. So $6 + 7$ is the double $6 + 6$ with 1 more.

Worked example: A near double

What is $8 + 9$?

Answer: 17

For grown-ups: Doubles show up everywhere: egg cartons (6 + 6), fingers (5 + 5), a spider’s legs (4 + 4). Point them out.

Practice

Pass with 3 right answers, the last 2 in a row. Each right answer earns 1 XP.

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Common Core State Standards for Mathematics, Grade 1, 1.OA.C.6: use strategies such as creating known sums, like 6 + 7 = 6 + 6 + 1
Institute of Education Sciences practice guide: Assisting Students Struggling with Mathematics: Intervention in the Elementary Grades (WWC 2021006)