← Back to Adding Doubles

Doubles - Worksheet 9 - 1st Grade

Hard

Learn doubles facts like 1+1, 2+2, 3+3 (Hard)

18 problems · 10-15 minutes · Skills: addition, doubles strategy

About This Worksheet

This hard-level worksheet contains 18 problems designed for 1st Grade students practicing adding doubles. Hard worksheets feature challenging problems including multi-step questions, missing values, and real-world applications to push students further.

Doubles facts are among the easiest to memorize and serve as anchor facts for solving nearby addition problems quickly.

  • Memorize doubles facts (1+1 through 10+10)
  • Use doubles to solve doubles-plus-1 and doubles-plus-2
  • Build mental math fluency
  • Connect doubles to even numbers and skip counting by 2s
  • Use doubles as anchor facts to solve nearby addition problems

How to Solve: Worked Example

Example Problem: 8 + 10 = ___
Solution Steps:
  1. This is "doubles plus 2": 10 = 8 + 2.
  2. Start with the double: 8 + 8 = 16.
  3. Add 2 more: 16 + 2 = 18.
Answer: 18
Tip: Doubles plus 2 works great: double the smaller number, then add 2.
1
10 + 10 = ___
2
7 + 7 = ___
3
0 + 0 = ___
4
3 + 3 = ___
5
9 + 9 = ___
6
4 + 4 = ___
7
5 + 5 = ___
8
6 + 6 = ___
9
1 + 1 = ___
10
8 + 8 = ___
11
2 + 2 = ___
12
10 + 10 = ___
13
7 + 7 = ___
14
0 + 0 = ___
15
3 + 3 = ___
16
9 + 9 = ___
17
4 + 4 = ___
18
5 + 5 = ___

Answer Key

1. 202. 143. 04. 65. 186. 87. 108. 129. 210. 1611. 412. 2013. 1414. 015. 616. 1817. 818. 10

Frequently Asked Questions

How do I download this doubles - worksheet 9 worksheet?

Click "Download PDF" for a file, or "Print" to use your browser. You can save it as a PDF or print it directly. The answer key will be on a separate page.

How do I find worksheets at different difficulty levels?

Each subtopic has 10 worksheets: Worksheets 1-3 are Easy, 4-7 are Medium, and 8-10 are Hard. Start with Easy worksheets to build confidence, then progress to harder ones.

What skills does this addition worksheet cover?

This worksheet focuses on addition, doubles strategy. It is designed for 1st Grade students and provides structured practice through varied problem types with a worked example to guide students before they begin.

Can I use this worksheet in my classroom?

Yes. All worksheets on K12Worksheets are free for classroom use. You can print copies for your entire class. With 10 worksheets per subtopic at three difficulty levels, you have plenty of options for differentiated instruction and individualized practice.

How many problems are on this worksheet?

This worksheet contains 18 problems. It typically takes 10-15 minutes to complete. An answer key with all solutions is included so parents and teachers can check work quickly.