Maths Year 1/2 Summer Addition and Subtraction

Day 1
Add 10, then 20, to 2-digt numbers, using Spider on a 1–100 grid. Begin with multiples of 10, then any 2-digit number. Record number sentences. Extend to adding 30.
Further Teaching with Y2
Use place value cards to model addition of pairs of 2-digit numbers by partitioning, e.g. 34 + 23, 45 + 24 (1s total less than 10),
then 46 + 25 (1s total greater than 10).
Group Activities: T with Y2
Y1 -- Choose 2-digit numbers and roll a dice to add 10, 20, or 30.
-- Pick a number on the grid and roll a dice to add up to 6 tens.
Y2 -- Play a card game to practise adding two 2-digit numbers.

Day 2
Add 10s and multiples of 10 on 1–100 grid.
Further Teaching with Y2
Children choose when to add 2-digit numbers by partitioning and recombining or by counting on in 10s and 1s. Discuss several examples and consider choices made.
Group Activities: T with Y2
Use the in-depth problem-solving investigation ‘Dicey Addition’ from NRICH as today’s group activity.
Or, use these activities:
Y1 -- Add a multiple of 10 to add to a number; record in a number sentence.
-- Calculate the missing number in an addition number sentence.
Y2 -- ‘Work backwards’ to suggest pairs of 2-digit numbers that add to make a given total.

• Large 1–100 grid
• Bean bag
• 1–100 grids (see resources)
• Plastic Spider
• Mini-whiteboards and pens
• 10s and 1s place value cards
• ITP Place Value
• Dice (stickered with two each of the numbers 10, 20 and 30)
• Counters
• 1–6 dice, 1-4 dice
• 10–50 tens cards
• 1–9 ones cards
• Place value cards
• ‘Numbers’ (see resources)
• ‘Number cards’ (see resources)
• ‘Spider counters’ (see resources, cut up into individual counters)
• Flipchart and pens
• 2-digit number cards

Day 1
Count on and back in 10s

Day 2
Count on and back in 10s from 1-digit numbers

Day 1
Y1: Add 10, 20, 30 or 40 to 1- or 2-digit numbers.
Y2: Add 2-digit numbers using partitioning: totals <90.
Add 2-digit numbers using partitioning: totals <100.

Day 2
Y1: Add 10p to 2-digit prices. Add 40p to 2-digit prices.
Y2: Add pairs of 2-digit numbers by partitioning or counting on.

Y1

• Complete each sentence:
  54 + 10 = ☐
  47 = 37 + ☐
  42 + 10 = ☐
• Write the number 20 more than:
  35
  95
  66
  21
• Complete each sentence:
  44 + 30 = ☐
  37 + ☐ = 57
  93 = ☐ + 30

Y2

• Look at the bar diagram (see download). Calculate the value of the missing number.
• Explain why it might help to change the order of this addition before you try to find the answer:
  15 + 62 = ☐
• Would you use counting on or partitioning to calculate these additions? Why? Find the answers.
  35 + 57 77 + 22 84 + 6

In-depth Investigation: Dicey Addition
Play a game of addition and strategy to reach a given total. Dicey Addition (Game 1) from nrich.maths.org. Vary the target number to make it easier or more difficult, e.g.
Y1 Closest to 100 wins
Y2 Total between 50 and 70 wins

Y1: Spider Adds
Adding 10 to 2-digit numbers.

Y2: Square Sums
Adding ‘friendly’ 2-digit numbers using partitioning (1s less than 10).

Day 1
Subtract 10s and multiples of 10. Model using Spider on a 1–100 grid.
Further Teaching with Y2
Introduce Maths Frog for finding differences by counting up. Model several calculations on 0–£1 penny lines, recording finding a difference as a subtraction.
Group Activities: T with Y2
Y1 Use the in-depth problem-solving investigation ‘Stop Me if You Can’ as today’s Y1 group activity.
Or, use this activity:
-- Create a 2-digit number; subtract 10 or a small multiple of 10s using a 1–100 number grid.
Y2 -- Find change from multiples (or near multiples) of 10p using Frog.

Day 2
Year 2 model an example of counting up for Y1 (54 – 38). Model subtraction by counting back (87 – 33) for everyone. Recognise that both are methods for subtraction and that Y2 are going to look at when it might be more efficient to use one method or the other.
Further Teaching with Y1
Subtract multiples of 10 on 1–100 grid.
Group Activities: T with Y2
Y1 -- Pick a starting number, roll a dice and subtract that multiple of 10.
-- Pick a number and pick a ‘subtract 10’ number card to create a number sentence.
Y2 -- Subtract two amounts of money, using different methods. Begin to reason about choices.

Day 3
Discuss several word problems, agree whether we will add or subtract to find an answer. Ask Y2 children to explain what strategy they might use to find the answer each time. Ask pairs to write word problems for given calculations.
Further Teaching with Y1
Further examples of solving money addition and subtraction problems (10ps and multiples of 10p).
Group Activities: T with Y2
Y1 -- Calculate price increases and decreases (multiples of 10p).
Y2 Use this Group Activity as this unit’s Y2 in-depth problem-solving investigation.
-- Solve addition and subtraction word problems. Create word problems and suggest strategies to solve.

• Large 1–100 grid
• Plastic Spider
• Mini-whiteboards and pens
• Counters
• ‘0–£1 penny line’ (see resources)
• Tens cards from 40–100
• ‘1–100 grids’ (see resources)
• Cards with 50p, 60p, 70p and 80p
• Items (e.g. pens, books etc.) labelled 37p, 29p, 46p and 26p
• Cards with 53p, 61p, 72p and 83p
• Flipchart and pens
• 6-sided dice adapted to show – 10, – 20 and – 30
• ‘Numbers’ (see resources)
• ‘Subtraction cards’ (see resources)
• ‘Count back’, ‘Always start with this amount’/ ‘Frog count up’, ‘Always start with this amount’/ ‘You choose’, ‘Spending the pound’ (see resources)
• ‘Addition and Subtraction Word Problems’ (see resources)
• 6-sided dice (or spinner) labelled – 10p, + 10p, + 20p, – 20p, + 30p, – 30p
• 5 items labelled 43p, 48p, 53p 62p and 65p
• ‘At the fruit bar’ Sheet 2 (see resources)

Day 1
Number bonds to 10

Day 2
Number bonds to 9

Day 3
Count on and back in 10s

Day 1
Y1: Subtract 10, 20, 30 or 40 from 2-digit numbers.
Y2: Find a difference between a multiple of 10 and a 2-digit number by counting up.
Find a difference between two 2-digit numbers by counting up.

Day 2
Y1: Subtract multiples 10; complete a missing number sentence.
Y2: Choose to subtract by counting up or counting back.

Day 3
Y1: Add and subtract 10s in word problems.
Y2: Find a difference between two 2-digit numbers in word problems.

Y1

• Write the number 20 less than:
  35, 95, 66, 21.
• Write the number 30 less than:
  51, 47, 32, 89.
• Complete each sentence:
  ☐ = 54 – 20
  63 – ☐ = 33
  12 = ☐ – 40

Y2

• Four purses contain the following amounts: 37p, 48p, 25p, 53p.
  Take 23p out of each purse. How much is left in each?
• Choose whether to use Frog to count up or whether to count back. Explain why you chose that method:
  62 – 38 66 – 33 75 – 6
  83 – 79 84 – 12 24 – 18
• Calculate the missing number in each bar model (see download).

In-depth Investigation

Y1 Stop Me if You Can
Children create diagonal lines on a 1-100 grid by adding and subtracting 10 and 1, whilst trying to stop their partner doing the same.

Y2 Problem writing
Use and apply skills from this unit by completing the ‘Problem-writing’ group activity from Day 3.

Y1: Spider Subtracts
Subtracting 10 from 2-digit numbers.

Y2: Pocket Money
Subtracting 11, 12, 13 from 2-digit numbers by counting back.