Short Blocks

# Maths Year 1/2 Summer Addition and Subtraction

Each unit has everything you need to teach a set of related skills and concepts.

### Planning and Activities

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.

### You Will Need

• 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

### Short Mental Workouts

Day 1
Count on and back in 10s

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

### Worksheets

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
Y2: Add pairs of 2-digit numbers by partitioning or counting on.

### Mastery: Reasoning and Problem-Solving

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