Doubles Plus 1 Addition Activity | Montessori-Inspired Mental Maths Cards

Help children move beyond memorising facts and begin using real mental maths strategies with this printable Doubles Plus 1 addition activity.

Once children know their doubles facts, they can use that knowledge to solve nearby facts quickly. For example, if a child knows 6 + 6 = 12, they can work out 6 + 7 = 13 by thinking “double 6, then add 1.”

This resource gives students focused, structured practice with the doubles plus 1 strategy, helping them build fluency, confidence, and flexibility with addition facts.

What’s Included

This printable maths resource includes:

• Doubles plus 1 addition practice
• Near-doubles addition facts
• Task cards or activity cards for repeated practice
• Mental maths strategy support
• Independent follow-up work
• Low-prep printable materials for classroom or homeschool use

Why This Resource Works

Many children can memorise some addition facts, but still count on their fingers when facts are only slightly different from ones they already know. This activity helps children notice patterns and use known facts to solve new ones.

It supports:

• Addition fact fluency
• Doubles facts recall
• Near-doubles strategy practice
• Mental maths confidence
• Number flexibility
• Early algebraic thinking
• Independent maths shelf work
• Small group intervention
• Homeschool maths practice

The doubles plus 1 strategy is especially useful because it teaches children to think mathematically rather than treating every fact as something separate to memorise.

Best For

This resource is ideal for:

• Montessori lower elementary maths
• Ages 6–9
• Homeschool addition practice
• Basic facts revision
• Mental maths lessons
• Independent maths shelf work
• Small group support
• Students who know doubles but need help applying them

Suggested Use

Use this activity after children have had practice with doubles facts such as 2 + 2, 5 + 5, and 8 + 8.

Children can work through the cards independently, with a partner, or in a small group. Encourage them to say the strategy aloud:
“I know the double, then I add one more.”

For children who still need concrete support, pair the cards with counters, bead bars, ten frames, or Montessori bead materials so they can physically build the double and then add one.

Created by Montessori Kiwi

Created by a Montessori-trained teacher and school leader, this resource is designed to help children build maths fluency through understanding, not pressure.

It saves you preparation time while giving children a clear, repeatable way to practise one powerful addition strategy.

Check out my Montessori number fact knowledge bundle or you may be interested in the following items:

Addition Tables
Subtraction tables
Multiplication Tables
Division Tables
Number Bonds 11-18
Number Bonds to 10
Coloured Bead Fact Families
Doubles plus 1
Adding Doubles
Teen Numbers

Check out our money saving maths bundle or junior math bundle.