Year 6, Unit 3, Week 1, Lesson 1 Written addition - Collins

Year 6, Unit 3, Week 1, Lesson 1

Written addition

National Curriculum attainment targets

? Practise addition and subtraction for larger numbers, using the formal written methods of columnar addition and subtraction

? Use estimation to check answers to calculation and determine, in the context of a problem, an appropriate degree of accuracy

Lesson objectives

? Add whole numbers using the formal written method of columnar addition

? Estimate and check the answer to a calculation

Previous related lessons none Prerequisites for learning Pupils need to: ? use the formal written method with six-digit numbers Vocabulary column addition, place value, carry

Future related lesson Unit 9, Week 1, Lesson 2 Success criteria Pupils can: ? write out the calculation correctly ? add each column ? carry the digit to the next column when needed

Getting Started

? Choose an activity from Number ? Addition and subtraction. ? Choose a game or activity from Fluency in Number Facts: Y5/Y6 ? Addition and subtraction.

Throughout the lesson, ensure that the digits are referred to by their place value not just as a one-digit number. So in 3 451 742, the digit 7 must be 1 referred to as 700. Read each calculation before working it out to ensure that children are aware of the whole number and not just focusing on individual digits.

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Continue with six-digit numbers.

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Resources mini whiteboard, pen and eraser (per child)

Year 6, Unit 3, Week 1

? Display: Slide 1.

? Say: Work out the calculation using the column method. Remember to lay your working out clearly so you do not miss any of the digits that you move to the next column.

? Watch the children's working out and notice any steps of which children are unsure.

? Work through the calculation as a class, asking different pairs to explain what needs to be done next and why. Focus on any aspects the class found tricky.

? Say: Estimating answers before working them out is a good way to check that answers are correct.

? Tell your partner how you would estimate the answer to the calculation we have just worked out. Ask some pairs to share their methods. Establish that rounding is a good way to estimate answers.

? Display: Slide 2.

? Say: Estimate the answer to this calculation together. Ask some pairs for their estimates and record them on the board.

? Say: Work out this calculation using the written method. ? Watch the children's working out and notice any steps of which children are unsure.

? Work through the calculation with the class, asking different children to explain what needs to be done next and why.

? Say: As the hundred thousand column added up to thirteen, we do not carry the one million, as it is the last column of the calculation. We make a million column so the answer is 1 308 225.

? Refer to the estimates and discuss if they confirm that the answer is correct.

? Display: Slide 3.

? Say: Estimate the answer to this calculation, then work it out together. ? Work through the calculation as a class. Ask: Did your estimate show you that your answer

was correct?

Unit 3: Number _ Addition and subtraction

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? Display: Slide 4.

? Say: Estimate the answer to this calculation then work it out.

? Work through the calculation as a class. Focus on any aspects children have found challenging.

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? Display: Slide 5.

? Ask: How can you use the written method to add this six- and seven-digit number together?

? Ask a pair to share their working. Check the rest of the class agree.

? Establish that digits with the same place value must be written out underneath each other.

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? Display: Slide 6.

? Say: Add these two numbers together.

Individualised Learning

Refer to Activity 1 from the Learning activities on page 154.

Pupil Book 6A ? Page 52: Written addition

Progress Guide 6 ? Support, Year 6, Unit 3, Week 1, Lesson 1: 5-digit addition

Plenary

mini white board, pen and eraser (per child)

? Say: Remind me when the written method is the best method to use. ? Ask some children to share their ideas. ? Write 365 299 + 294 999 on the board. ? Ask: What do you think is the best way to work out this calculation? ? Ask some pairs to share their ideas. Establish that, as both numbers can be easily rounded, a

mental method would be very efficient for this calculation. ? Say: If I round 365 299 to 365 300, and 294 999 to 295 000 then I can easily add them

mentally and adjust the answer. ? Talk children through your mental addition strategy. You may want to make jottings as you

do this. ? Say: Write down a similar calculation that would be better added mentally. ? Ask some pairs to share their calculation with the class. The rest of the class work it out mentally.

Overcoming Barriers

? If children are making mistakes with the formal written method, it indicates they do not have a secure understanding of why the method works. Children who do understand the method can apply it to any numbers. Use four- or five-digit numbers and show the adding of each column separately alongside the written method so children can clearly see the place value of each answer, for example, thousands add thousands.

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