Short Blocks

Maths Year 1 Summer Addition & Subtraction (A)

Each unit has everything you need to teach a set of related skills and concepts. 'Teaching for Understanding' provides whole-class teaching and fully differentiated adult-led group activities. ‘Problem-solving and Reasoning’ develops these skills, and includes questions to enable you to assess mastery. Practice sheets ensure procedural fluency. Extra support activities enable targeted work with children who are well below ARE.

‘UNIT PLAN’ gives you a text version of all parts of the unit to use in your school planning documentation. ‘DOWNLOAD ALL FILES’ gives you that unit plan plus all of associated documents. These bulk downloads are added value for Hamilton Friends and School Subscribers.

Unit 1 Add 10s and near 10s to a 2-digit number (suggested as 2 days)

Objectives

Add 10s and near 10s to a 2-digit number
Unit 1: ID# 1847

National Curriculum
Add/Sub (i) (ii) (iii) (iv)

Hamilton Objectives
11. Add numbers by counting on.
10. Recognise the + and – and = signs, and use these to read and write simple additions and subtractions.
12. Solve missing number problems and addition/subtraction problems in number stories.

Teaching and Group Activities for Understanding

Day 1 Teaching
Show children a 1–100 grid. Remind me how Spider can help us to add. Point at 21. Model how Spider counts in 10s down the grid. Use Spider to help children find 10 more than any number. Record each calculation like this: 21 + 10 = 31. Then progress to 20 more.
Group Activities
-- Roll a dice to generate a number of 10s to add to a number. Add and record a number sentence.
-- Choose a 2-digit number, then +10, 20 and 30 to it.
-- Work out the missing number in an addition number sentence.

Day 2 Teaching
Write 53 + 11 = __ on the board. Point at 53 on the 1-100 number grid. Demonstrate what 50 + 10 is using Spider. Then use Fly to add 1 more. Record: 53 + 11 = 64. Repeat this to demonstrate how we use Spider and Fly to help us add 11 to a multiple of 10, e.g. 30, i.e. Fly moves down to the beginning of the next row. Ask children to collaborate to add 11 to 44 and to 38.
Group Activities
-- Work out the new price for the stationery after a price increase of 11p.
-- Explore the 100 grid to add 11 to a range of numbers. Work backwards to find a starting number.

You Will Need

  • 1-100 number grid (see resources)
  • Plastic spider and fly
  • Bean-bag
  • ‘Numbers’ sheet (see resources)
  • Additional activity sheets (see resources)
  • 1-4 dice and counters
  • Flipchart
  • Items of stationery with price labels

Mastery: Reasoning and Problem-Solving

  • Complete each sentence.
    54 + 10 = ☐
    37 + ☐ = 47
    42 + 10 = ☐
    ☐ + 11 = 86
    66 + ☐ = 77
  • Add 11 to each number.
    83 24 18 46
  • True or false?
    -- Adding 11 to numbers with 2 digits the same (like 22 or 33) always gives another number with 2 digits the same.
    -- Adding 10 to a number where the first digit is 1 less than the second digit (like 12 or 23) always gives an answer with 2 digits the same.

In-depth Investigation
None for this unit.

Unit 2 Subtract 10s/nr 10s from 2-digit numbers (suggested as 3 days)

Objectives

Subtract 10s and near 10s from a 2-digit number
Unit 2: ID# 1861

National Curriculum
Add/Sub (i) (ii) (iii) (iv)

Hamilton Objectives
11. Subtract numbers by counting back.
10. Recognise the + and – and = signs, and use these to read and write simple additions and subtractions.
12. Solve missing number problems and addition/subtraction problems in number stories.

Teaching and Group Activities for Understanding

Day 1 Teaching
Place Spider on 48 on a 1–100 number grid. We know that Spider moves down the grid to add 10s, so which way does she move to subtract 10s? Children discuss and give examples. Write 48 – 20 = __. Spider is on 48 but we want to subtract 20. How can she help us do this? Ask a child to demonstrate. Record: 48 – 20 = 28.
Repeat with other numbers, e.g. 53, 71, 99, 86, subtracting different numbers of 10s.
Do a ‘Silent Subtraction’: without talking, move Spider to show a calculation; children watch carefully and write a number sentence to show her moves. Repeat.
Ask a child to do a ‘Silent Subtraction’.
Group Activities
-- Pick a number, roll a dice and subtract that amount of 10s.
-- Pick a number and pick a ‘subtract 10’ number card to create a number sentence.

Day 2 Teaching
Write 53 - 11 = __ on the board. Point at 53 on the 1-100 number grid. Demonstrate what 50 - 10 is using Spider. Then use Fly to subtract 1 more. Record: 53 - 11 = 42. Repeat this to demonstrate how we use Spider and Fly to help us subtract 11 from 41. Ask children to collaborate to subtract 11 from 43 and from 37.
Group Activities
Use the ‘Stop me if you can’ in-depth problem-solving investigation below as today’s group activity.
Or, use these activities:
-- Work out new prices after an 11p reduction.
-- Work out new prices after a 21p reduction.

You Will Need

  • 1-100 number grid (see resources)
  • Plastic spider, fly and bean bag
  • Flipchart
  • Mini-whiteboards and pens
  • 6-sided dice adapted with -10, -20, -30 number stickers
  • ‘Numbers’ sheet (see resources)
  • ‘Subtraction cards’ sheet (see resources)
  • Counters and items with price labels

Mental/Oral Maths Starters

Suggested for Day 1
Count in 10s from single-digit numbers (simmering skills)

Suggested for Day 2
Number bonds to 10 (simmering skills.

Procedural Fluency

Day 1
Find out the number of 10s subtracted in incomplete number sentences.

Day 2
Help the shop-keeper reduce the prices in his shop by 11p.

Mastery: Reasoning and Problem-Solving

  • Write the number 20 less than…
    35, 95, 66, 21
  • Complete each sentence
    36 – 11 =
    45 – 11 =
    50 – 11 =
  • Start at 82. Count back 11 three times. What is your answer?

In-depth Investigation: 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.

Extra Support

Spider Subtracts
Subtracting 10 from 2-digit numbers

Unit 3 Add/subtract 10, 11, 12 (suggested as 3 days)

Objectives

Add/subtract 10, 11, 12
Unit 3: ID# 1871

National Curriculum
Add/Sub (i) (ii) (iii) (iv)

Hamilton Objectives
11. Add numbers by counting on and subtract numbers by counting back.
10. Recognise the + and – and = signs, and use these to read and write simple additions and subtractions.
12. Solve missing number problems and addition/subtraction problems in number stories.

Teaching and Group Activities for Understanding

Day 1 Teaching
Briskly recap adding and subtracting 11 using Spider and Fly on a 1-100 number grid [Unit 1: Day 2 & Unit 2: Day 2], e.g.
52 + 11 = __, 37 + 11 = __, 60 + 11 = __
78 – 11 = __, 93 – 11 = __, 51 - 11 = __
Perform a ‘Silent Subtraction’, asking children to record the number sentence. Perform an ‘Action-only Addition’ (like a Silent Subtraction!) asking children to record the number sentence.
Group Activities
-- Repeatedly add or subtract 11 from starting numbers on a 1-100 number grid.

Day 2 Teaching
Challenge children to find 34 + 12. Could we use Spider and Fly to help? Allow children time to think-pair-share. Model calculation; record a number sentence. Repeat for 53 – 12. Discuss and model how to find the numbers in a ‘Chain’, e.g. 45 + 10 – 11 (55 and 43), then 49 + 11 – 10.
Group Activities
Use today’s whole class activity - Empty Chains - as this unit’s In-depth investigation.
-- Calculate the sequence of numbers in a chain; describe and attempt to explain number patterns.

You Will Need

  • ‘1-100 number grid’ (see resources)
  • Counters
  • Plastic spider and fly
  • ‘Empty chains’ sheets 1 and 2 (see resources)
  • Mini-whiteboards and pens

Procedural Fluency

Day 1
Working out the right ages for the birthday balloons by adding/subtracting 11.
Adding and subtracting 11.

Day 2
Work out number sentence pairs adding/subtracting 11 and 12.

Mastery: Reasoning and Problem-Solving

  • Add 11 to 32.
    Then add 11 to the answer.
    Then add 11 to the answer.
    How long can you continue this?
  • Subtract 11 from 87.
    Then take 11 from the answer.
    Subtract 11 again.
    How long can you continue this?
  • Complete the triangle (see download) by writing the missing number. The 3 corner numbers add up to the one in the middle!

In-depth Investigation: Empty Chains
See the Day 2 group activity for more detail. Use Spider and Fly to help calculate a sequence of numbers in a ‘chain’. Describe and attempt to explain number patterns.

Extra Support

Use the ‘Working towards’ Group Activity from Day 1 as this Unit’s Extra Support.