Year 4: Addition and subtraction × Add and subtract numbers with up to 4 digits using the efficient written methods of columnar addition and subtraction where appropriate New Maths Curriculum (2014): Year 4 objectives. Add and subtract numbers with up to 4 digits using the efficient written methods of columnar addition and subtraction where appropriate ? × Estimate and use inverse operations to check answers to a calculation A new resource to help teach this objective will be added soon. New Maths Curriculum (2014): Year 4 objectives. Estimate and use inverse operations to check answers to a calculation ? × Solve addition and subtraction two-step problems in contexts, deciding which operations and methods to use and why. New Maths Curriculum (2014): Year 4 objectives. Solve addition and subtraction two-step problems in contexts, deciding which operations and methods to use and why. ?