Maths Year 3/4 Summer Addition & Subtraction (B)

Day 1
Model using Frog to find change from £5, £10 and £20 when buying one or several items.
Group Activities: T with Y3
Y3 -- Practise finding change from £5, £10 and £20.
-- Choose two items that add up to under £5, £10 or £20, then calculate change.
Y4 -- Buy multiple items that add up to under £20, then calculate change.
-- Choose two items that add up to under £5, £10 or £20, then calculate change.

Day 2
Model using Frog to find change from £100 when buying several items. Represent problems with a bar model.
Group Activities: T with Y4
Y3 Use the in-depth problem-solving investigation ‘Step Change’ as today’s group activity.
Or, use these activities:
-- Practise finding change from £100 for a range of items.
-- Play ‘Change from £100 pairs’.
Y4 -- Practise finding change from £100 when buying 2 or 3 items.

Day 3
Model finding differences using Frog, e.g. a game costs £18, if I have £7.55 how much more will I need to save?
Further Teaching with Y4
Use Frog to calculate differences between two amounts: £28.84 and £32.37; £23.24 and £18.78.
Group Activities: T with Y3
Y3 -- Calculate how much more money is needed to pay for a range of items.
-- Calculate how much more money is needed to pay for a more expensive version of an item.
Y4 -- Find the difference between two amounts of money.

Day 4
Explore a range of 3-digit subtractions to discuss the choice of most appropriate/efficient strategies.
Further Teaching with Y4
Reasoning about when to use mental or written subtraction in a range of examples.
Group Activities: T with Y4
Y3 -- Subtract two 3-digit numbers, beginning to recognise when to use each of two different mental strategies.
-- Find the mystery missing numbers that have been subtracted from 3-digit numbers.
Y4 -- Justify choices for, then use, mental or written strategies for subtraction.
-- Sort calculations according to whether they are more efficiently solved mentally or using a written method.

Day 5
Discuss several word problems. Would you use addition or subtraction calculations? Discuss how a sketch, number line or bar model can support visualisation before answering.
Group Activities: T with Y3
Y4 Use the in-depth problem-solving investigation ‘Prime Addition Squares’ as today’s group activity.
Or, use these activities:
Y3/Y4 -- Solve single-step word problems in a group, then in pairs.
-- Fill the gaps with missing numbers in multi-step number stories.

• Mini-whiteboards and pens
• Items that might be for sale in a seaside shop, e.g. sun cream, beach towel, bucket, spade with prices £2.74, £1.43, £8.53 and £5.72
• Toy labelled £4.67; a real £5 and £10 note
• ‘Finding change’ (see resources)
• ‘Penny lines’ (see resources)
• ‘The beach shop’ (see resources)
• Coins
• 1–6 dice
• Calculators
• ‘Finding change from £100’ (see resources)
• ‘Finding change from £20’ sheets (see resources)
• ‘Set A’ and ‘Set B’ game cards (cut up and separated into two piles for each game, see resources)
• Picture of a console/computer game
• ‘How much more?’ Sheets 1 and 2 (see resources)
• ‘0–£1 penny line’ (see resources)
• ‘Items for sale’ sheet (see resources)
• ‘Money cards’ Sets A and B’ (see resources)
• Flipchart and pens
• ‘Mental or written?’ Sheet 1 and 2 (see resources)
• Red and blue interactive whiteboard pens
• ‘Subtracting mentally’ (see resources)
• ‘Word problems’ Sheet 1 and 2 (see resources)
• Sticky notes

Day 1
Add to the next 10

Day 2
Subtraction facts to 20

Day 3
Count on in steps of 10p from any amount

Day 4
Add/subtract multiples of 10 and 100 to/from 3-digit numbers

Day 5
Match digital and analogue times

Day 1
Y3 Find change from £5, £10 or £20.
Y4 Find change from £5, £10 or £20.

Day 2
Y3 Find change from £20 or £100.
Y4 Find change from £50 or £100.

Day 3
Y3 How much more (comparing costs)?
Y4 Find differences (money).

Day 4
Y3 Subtract mentally.
Y4 Mental or written subtraction?

Day 5
Y3 Addition and subtraction word problems.
Y4 Addition and subtraction word problems.

Y3

• Calculate the change from £10 when buying:
  Key ring £5.68
  Cards £7.75
  Pen £6.43
• Calculate the change from £50 when buying:
  Game £34.75
  Controller £42.56
  Case £28.67
• Calculate the change from £100 when buying:
  Game £67.43
  Console £85.85
  Tablet £73.68

Y4

• Write the missing numbers:
  £26.67 = £100 – ☐
  9381 – 5864 = ☐
  1001 – ☐ = 784
• True or false? Explain your ideas:
  -- Subtracting from a multiple of 1000, it is best to use Frog.
  -- Subtracting a 3-digit number from a 4-digit number always gives an answer greater than 1000.
  -- Subtracting 4827 from 7284 will only involve moving amounts from 1 column.
  -- Subtracting 895 from 2222, column subtraction is not the ‘best’ method.

Y3 In-depth investigation: Step Change
Children find change from 2 or 3 notes. They explore patterns in the pence.

Y4 In-depth investigation: Prime Addition Squares
Children add sets of three 3-digit numbers to find patterns in a magic square based on prime numbers.

Y3: Read it
Finding change from £1.

Y4: Pick ‘n’ Mix
Using place value to add and subtract to/from 3-digit numbers.

Day 1
Model adding three 3-digit numbers using expanded and compact addition. Estimate by rounding to the nearest 100.
Further Teaching with Y4
Model solving 4-digit subtractions using decomposition, discuss how to recognise the number of column ‘moves’.
Group Activities: T with Y3
Y3 -- Practise adding trios of 3-digit numbers, using either expanded or compact addition (totals less than 1000 and greater than 1000).
Y4 -- Secure use of expanded column subtraction to subtract pairs of 4-digit numbers.
-- Consolidate use of expanded column subtraction to subtract pairs of 4-digit numbers.

Day 2
A confident Y4 shows Y3s how they solve 5721 – 3456 using column subtraction.
Further Teaching with Y3
Model using column addition to solve money problems.
Group Activities: T with Y3
Y3 -- Practise using expanded or compact addition to add amounts of money.
-- Estimate then calculate multiple costs that add to less than £10.
Y4 -- Use digits 2–9 to create 4-digit compact subtractions needing 3 moves.
-- Use digits 3–8 to create 3-digit compact subtractions needing 2 moves.

Day 3
Discuss a range of additions that illustrate use of different strategies, including mental methods (place value and ‘add and adjust’).
Further Teaching with Y4
Share the thinking behind what to look for when choosing calculation methods (all four operations).
Group Activities: T with Y4
Y3 Use the in-depth problem-solving investigation ‘Mobile Towers’ as today’s group activity.
Or, use these activities:
-- Add two 3-digit numbers, beginning to recognise when to use each of two different mental strategies.
-- Pick two cards and decide if using a written method for addition or a mental calculation is more efficient.
Y4 Use the ‘Prime Addition Squares’ in-depth problem-solving investigation below as today’s group activity.
Or, use these activities:
-- Choose methods for a range of calculations (all operations); justify choices.

• ‘Adding three 3-digit numbers’ Sheets 1 and 2 (see resources)
• ‘Adding pairs of 3-digit numbers’ Sheet 3 (see resources)
• ‘Bicycles for sale’ (see resources)
• ‘Column subtraction’ (see resources)
• ‘Adding amounts of money’ Sheets 1 and 2 (see resources)
• Flipchart and pens
• Books with price tags: £4.79, £3.14, £6.01, £5.49, £5.88, £5.25, £3.23, £4.65, £4.29, £2.35, £5.17, £2.52
• 2–9 digit cards
• Calculators
• ‘Choosing how to do calculations’ Sheets 1 and 2 (see resources)
• ‘Adding mentally’ (see resources)
• 100s, 10s and 1s place value cards
• ‘3-digit number cards’ Sheets 1 and 2 (see resources - cut into cards)
• A3 paper
• Mini-whiteboards and pens

Day 1
Add three multiples of 10

Day 2
Complements to £1

Day 3
Subtract pairs of 2-digit numbers

Day 1
Y3 Target numbers: add 3-digit numbers.
Y4 Column subtraction.

Day 2
Y3 Add money.
Y4 More column subtraction.

Day 3
Y3 Methods for adding 3-digit numbers.
Y4 Choose how to do calculations.

Y3

• Use a different method to add each pair of numbers:
  682 + 199
  365 + 532
  26 + 35 + 74
• Choose three of these numbers and write an estimate of their total:
  475, 386, 287, 349, 248.
  Add the three numbers and compare the actual answer with your estimate. Repeat, choosing three different numbers. Was your second estimate closer?
• Work out the missing numbers in this addition puzzle:
  £4 ☐p 8p
  £7 80p ☐p
  £☐ 60p 1p

Y4

• Use a different method to add each pair of numbers:
  3682 + 199
  4385 + 3784
  26 + 35 + 74
• Use a different method to find the difference between each pair of numbers:
  3483 – 201
  5005 – 3896
  7624 – 4378
• Use these digits: 5, 8, 3.
  Create two 3-digit numbers by placing the digits in a different order.
  Add these two numbers: this is answer A.
  Find the difference between these numbers: this is answer B.
  Find the difference between A and B.
  Double the smaller of your first 2 numbers.
  What do you notice?

Y3 In-depth investigation: Mobile Towers
Children create four or five 2-digit numbers and add these to get different totals.

Y4 In-depth investigation: Prime Addition Squares
Children add sets of three 3-digit numbers to find patterns in a magic square based on prime numbers.

Y3: Addition of 3-digit Numbers
Using the interactive tool from Harcourt School at http://www.harcourtschool.com, children use base-10 blocks to explore regrouping in addition.

Y4: Pick ‘n’ Mix – Using place value to add and subtract to/from 3-digit numbers.