Mental strategies in addition - add on numbers up to 30

  • Mental strategies in addition - add on numbers up to 30
  • Course: Mathematics
  • Grade: Year 4
  • Section: Addition
  • Outcome: Two digit addition - Problem Solving
  • Activity Type: Printable
  • Activity ID: 3670


“What a brilliant site you have!!! I love it, especially as it saves me hours and hours of hard work. Others who haven't found your site yet don't know what they are missing!”
Patricia Celikbilek, Teacher
aasl award

Awarded June 2012
“Best Educational Website
for Teaching and Learning”

United Kingdom – National Curriculum expand/collapse

  • KS2 – Key Stage 2
    • KS2.Ma2 – Number and algebra
      • Knowledge, skills and understanding

        • Solving numerical problems

          • KS2.Ma2.4 – Pupils should be taught to:

            • KS2.Ma2.4.a – Choose, use and combine any of the four number operations to solve word problems involving numbers in 'real life', money or measures of length, mass, capacity or time, then perimeter and area

        • Using and applying number

          • KS2.Ma2.1 – Pupils should be taught to:

            • Problem solving

              • KS2.Ma2.1.a – Make connections in mathematics and appreciate the need to use numerical skills and knowledge when solving problems in other parts of the mathematics curriculum

        • Numbers and the number system

          • KS2.Ma2.2 – Pupils should be taught to:

            • Counting

              • KS2.Ma2.2.a – Count on and back in tens or hundreds from any two- or three-digit number; recognise and continue number sequences formed by counting on or back in steps of constant size from any integer, extending to negative integers when counting back

        • Calculations

          • KS2.Ma2.3 – Pupils should be taught to:

            • Number operations and the relationships between them

              • KS2.Ma2.3.a – Develop further their understanding of the four number operations and the relationships between them including inverses; use the related vocabulary; choose suitable number operations to solve a given problem, and recognise similar problems to which they apply

            • Mental methods

              • KS2.Ma2.3.e – Work out what they need to add to any two-digit number to make 100, then add or subtract any pair of two-digit whole numbers; handle particular cases of three-digit and four-digit additions and subtractions by using compensation or other methods [for example, 3000 - 1997, 4560 + 998]

            • Written methods

              • KS2.Ma2.3.i – Use written methods to add and subtract positive integers less than 1000, then up to 10000, then add and subtract numbers involving decimals; use approximations and other strategies to check that their answers are reasonable

Australia – Australian Curriculum expand/collapse

  • Year 3
    • Number and Algebra
      • Number and place value

        • ACMNA055 – Recall addition facts for single-digit numbers and related subtraction facts to develop increasingly efficient mental strategies for computation

New Zealand – National Standards expand/collapse

  • 5 – Year 5
    • 5.NA – Number and algebra
      • 5.NA.1 – Apply additive and simple multiplicative strategies and knowledge of symmetry to:

        • 5.NA.1.a – Combine or partition whole numbers

United States – Common Core State Standards expand/collapse

  • 2 – Grade 2
    • 2.OA – Operations & Algebraic Thinking
      • Mathematics

        • 2.OA.1 – Use addition and subtraction within 100 to solve one- and two-step word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem. (See Glossary, Table 1. )

    • 2.NBT – Number & Operations in Base Ten
      • Mathematics

        • 2.NBT.5 – Fluently add and subtract within 100 using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction.