Adding and Subtracting 1s

By the end of this unit, children will be able to:

1. Add and subtract 1s from a given number.
2. Use a range of models and representations, including place value chart, to explore the effect of adding or subtracting multiples of 100.
3. Understand that when adding or subtracting 100s, only the hundreds place value column changes and the tens and ones remain the same.
4. Use number bonds to and within 10 to support in this step.

Curriculum Alignment: Year 2 Number: Addition and subtraction

• Solve problems with addition and subtraction:
  • using concrete objects and pictorial representations, including those involving numbers, quantities and measures
  • applying their increasing knowledge of mental and written methods
• Recall and use addition and subtraction facts to 20 fluently, and derive and use related facts up to 100
• Add and subtract numbers using concrete objects, pictorial representations, and mentally, including:
  • a two-digit number and 1s
  • a two-digit number and 10s
  • 2 two-digit numbers
  • adding 3 one-digit numbers
• Show that addition of 2 numbers can be done in any order (commutative) and subtraction of 1 number from another cannot
• Recognise and use the inverse relationship between addition and subtraction and use this to check calculations and solve missing number problems