# Maths Year 3/4 Spring Addition and Subtraction

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

## Mental addition and subtraction(suggested as 4 days)

### Planning and Activities

Day 1 Teaching
Discuss what strategies we can use to add two 2-digit numbers, and then how we can use those same strategies to add a 2-digit number to a 3-digit number. Use the same strategies to add pairs of 3-digit numbers where a mental strategy would be quicker than column addition.
Group Activities: T with Y3
Use the ‘Make 100’ in-depth problem-solving investigation below as today’s group activity.
Or, use these activities:
Y3 -- Use spinners to generate 2-digit numbers to add. Children discuss which strategy they used each time.
Y4 -- Decide when additions can be efficiently solved using a mental strategy rather than column addition. Some children will find trios with a total of 100, then 200.

Day 2 Teaching
Children subtract 20p, then 21p and 19p from prices.
Further Teaching with Y4
Use Frog to find out how much further cyclists need to cycle from 625 to 874 miles. Sketch a bar model to represent this.
Group Activities: T with Y4
Y3 -- Reduce prices by near multiples of 10p; Reduce prices by 32p and 29p.
Y4 -- Use counting up to find the difference between two 3-digit numbers.

Day 3 Teaching
Show children items with prices tags less than £5 and a £5 note. Together calculate the change using Frog. Repeat, finding the change from £10.
Further Teaching with Y3
Revise using Frog to subtract pairs of 2-digit numbers.
Group Activities: T with Y3
Y3 -- Frog investigation: think of a 2-digit number, 1st digit greater than 2nd, reverse and subtract, e.g. 85 – 58.
Y4 -- Count up to find change from £5 and £10.

Day 4 Teaching
Discuss choosing Frog or counting back to subtract 2-digit numbers. Begin to recognise what it is about the numbers that informs this choice.
Further Teaching with Y4
Show a table of items with their ‘old’ and ‘sale’ prices. Demonstrate how to use Frog to count up to find the difference between each pair of prices.
Group Activities: T with Y4
Y3 -- Choose Frog or counting back to subtract; explain choices.
Y4 -- Count up to find the difference between two amounts of money; use addition to check answers to subtractions.

### You Will Need

• Large 100-square
• Plastic or card spider and fly
• ‘2-digit number spinners’ sheets 1 and 2 (see resources, enlarge to A3)
• ‘1 to 100 number grid’ (see resources)
• Tens and one place value cards
• ‘Subtracting near multiples’ sheets 1 and 2 (see resources) or label actual items with the tags
• Items with price tags less than £5, between £5 and £10, a £5 note and a £10 note
• Toy frog
• 0–100 beaded and landmarked number lines to display on the IWB (see resources)
• ‘0–100 landmarked number lines’ (see resources)
• ‘Number cards’ sheet 1 and 2 (see resources)

Day 1

Day 2

Day 3
Change from £1

Day 4
Pairs to 100

### Worksheets

Day 1
Y3: Use Spider and Fly to add pairs of numbers which don’t cross 10s. Add pairs of amounts of money.
Y4: Complete missing numbers in an addition grid; add 3-digit and 2-digit numbers.

Day 2
Y3: Subtract 2-digit numbers by taking away 10s and 1s, or by subtracting a multiple of 10 and adjusting.
Y4: Use empty number lines to subtract pairs of 3-digit numbers by counting up.

Day 3
Y3: Practise using Frog to subtract pairs of 2-digit numbers.
Y4: Find change from £5 and £10 by counting up.

Day 4
Y3: Choose Frog or counting back to calculate given subtractions.
Y4: Draw empty number lines and find the difference between two amounts of money by counting up.

### Mastery: Reasoning and Problem-Solving

Y3

• Use a different strategy for each of these additions:
45 + 29
45 + 34
65 + 35
78 + 28
• Write the missing numbers:
(a) ☐ + 30 = 55
(b) 100 - 79 = ☐
(c) ☐ + 19 = 65
(d) 73 – ☐ = 58
(e) 50 – ☐ = 43
(f) ☐ + 47 = 62
• Hassan spends 39p on a drink. He uses a 50p coin to pay. How much change does he get?
• Sam has 76 cards. Tom has 92. How many more does Tom have than Sam?

Y4

• Tim buys a DVD and Frog finds the change from £10. He says it is £3.46. How much was the DVD?
• Complete each diagram:
 £10 £6.83 ?
 £5 ? £2.27
 £10 £3.58 ?
• Write a list of ‘Top Tips’ for how you would find the difference between these two prices: £4.52 and £6.18.

In-depth investigation: Make 100
Given a pattern of four 1-digit numbers, children attempt to make a total of exactly 100.

### Extra Support

Y3: Hop, Jump and Hop
Subtracting pairs of 2-digit numbers either side of a multiple of 10, e.g. 54 – 37, using counting up (Frog)

Y4: Winter Warmers
Finding the change from £5 (answers less than £1)

Are We Nearly There Yet?
Using counting up (Frog) to subtract numbers either side of 100, e.g. 102 – 97 and 102 – 78