Free printable practice
Adding Doubles Minus 1 Practice Activities
Printable maths practice that helps children use known doubles facts to solve addition facts such as 6 + 5 or 8 + 7 quickly and accurately.
Practice that builds confidence
From doubles to near doubles
These Adding Doubles Minus 1 worksheets help children build fluency with near-doubles addition facts. Children practise noticing when two addends are almost the same, then using a known double to find the sum with less counting.
The printable activities include focused addition drills and varied fact practice around the doubles-minus-1 strategy. They are useful for home revision, maths warm-ups, extra practice after teaching doubles, or confidence-building work with addition facts.
In this Mathematics > Math Drills > Addition Facts collection, children work on sums where one number is 1 less than the other. Instead of counting every item, they connect the fact to a double they already know. For example, 7 + 6 can be thought of as 7 + 7 - 1, and 9 + 8 can be solved as 9 + 9 - 1. This strengthens mental maths and helps addition facts feel connected rather than memorised one by one.
How the skill progresses
Children first need secure doubles facts such as 4 + 4, 6 + 6, and 8 + 8. The worksheets then guide them to recognise adjacent addends, choose the helpful double, subtract 1, and write the sum. With repeated practice, they begin to see 5 + 4, 6 + 5, and 8 + 7 as related facts instead of new calculations.
A simple parent routine
At home, begin with three quick doubles aloud: “What is 6 + 6?” Then show a near double: “So what is 6 + 5?” Ask your child to say the thinking, not just the answer: “Double 6 is 12, minus 1 is 11.” Let them complete a short section, then circle two sums and explain the strategy back to you. If they count on fingers, gently return to the double: “Which double is this almost?”
Classroom uses for teachers
Teachers can use these printables as lesson practice after introducing doubles, morning maths drills, small-group support, or independent work at centres. They also work well for quick checks: pupils who can identify the related double are ready for mixed addition facts, while pupils who hesitate may need more doubles review using counters, ten-frames, or number bonds.
Common errors to watch for
Some children double the smaller number and subtract 1, which gives an answer that is too small. Others spot the double but forget the “minus 1” step. Reversing the addends is fine because addition is commutative, but the reasoning should still match the numbers. Encourage children to mark the bigger addend, double it, and then reduce by 1.
Free printable PDF download
Use this adding doubles minus 1 worksheet page to preview the activity, print it, or download it as a PDF for quick practice. It works well for homework, homeschool lessons, tutoring, morning work, revision, and classroom centers.
Answers and answer key support
After the child completes the worksheet independently, parents and teachers can use the answer support or answer key information to check the work, review mistakes, and choose the next practice step.
Why iBloom worksheets help
iBloom worksheets keep the focus narrow so children can practise one efficient strategy until it becomes automatic. The layout supports repeated, purposeful practice without too many distractions. A child-friendly reminder is: “Find the bigger number, make its double, take away 1.”
Helpful answers
Frequently asked questions
What does adding doubles minus 1 mean?
It means solving an addition fact where one addend is 1 less than the other by using a double. For example, 8 + 7 can be solved as 8 + 8 - 1 = 15.
Which doubles facts should my child know first?
Your child should be comfortable with basic doubles such as 3 + 3, 5 + 5, 7 + 7, and 9 + 9 before using the doubles-minus-1 strategy confidently.
Is 6 + 5 solved by doubling 6 or doubling 5?
For the doubles-minus-1 method, it is usually easiest to double the bigger number: 6 + 6 = 12, then subtract 1 to get 11. Doubling the smaller number and adding 1 also works, but children should not mix the steps.
How can I tell if my child is using the strategy and not just guessing?
Ask them to explain the related double. A strong answer sounds like, “9 + 8 is almost 9 + 9. 9 + 9 is 18, so the answer is 17.”
Can these worksheets be used after teaching regular doubles?
Yes. They are especially useful after children have practised doubles facts, because the worksheets help them extend that knowledge to near-doubles addition facts.
Is this adding doubles minus 1 worksheet free?
Yes. You can preview it for free and use the printable worksheet for home or classroom practice.
Can I download this adding doubles minus 1 worksheet as a PDF?
Yes. Use the worksheet download option to save a printable PDF, or print the worksheet directly from the page.
Does this adding doubles minus 1 worksheet include answers or an answer key?
When the activity has fixed answers, iBloom includes answer support so parents and teachers can check the completed worksheet.