Addition and subtraction

• Add and subtract numbers mentally, including:
• A three-digit number and 1s
• A three-digit number and 10s
• A three-digit number and 100s
• Add and subtract numbers with up to 3 digits, using formal written methods of columnar addition and subtraction
• Estimate the answer to a calculation and use inverse operations to check answers
• Solve problems, including missing number problems, using number facts, place value, and more complex addition and subtraction