Short Blocks

Maths Year 4 Summer Decimals and Fractions (B)

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

Add/subt 0.1s & 0.01s; measures problems (suggested as 3 days)

Planning and Activities

Day 1 Teaching
Today we’re going to use two familiar resources that both represent or show numbers from 0.01 to 1 – the bead bar and the 100 square. Use tags to mark the tenths on a bead bar; count along in tenths, then hundredths. Show a blank 100 square with just 0.01, 0.02, and 0.03 marked. Discuss what number will be at the end of the top row/ in the square under that/ in the bottom right corner. Mark other numbers on the square. What size steps are we counting in going down the grid?
Group Activities
-- Use counting on and back in tenths or hundredths to fill in missing adjacent numbers in a 0.01–1 square.
-- Fill in a row and column of a 0.01–1 square; identify the numbers in ‘crosses’ drawn on the 0.01–1 square.
-- Work backwards to identify starting numbers when adding/subtracting tenths and hundredths.

Day 2 Teaching
Display the 0.01–1 square. Count in steps of 0.01 from 0.3 to 0.4, then back, then in steps of 0.1 from 0.05 to 0.95 and back. Write 0.35 + 0.4 and model, using the 0.01–1 square: start at 0.35, count on 0.4. Which digit changes? Repeat for 0.35 – 0.04 and 0.35 – 0.4.
Group Activities
Use the ‘Decimals in a row’ in-depth problem-solving investigation below as today’s group activity.
Or, use these activities:
-- Play a game adding and subtracting hundredths on a completed or blank 0.01–1 square.

Day 3 Teaching
Write: A snail has crawled 2.34m. It crawls 4cm more. How far has it crawled now? What calculation do we need to do? Which digit will change when we add 4cm? Why? Establish that 4cm is the same as 4/100 of a metre or 0.04m. Write the number sentence: 2.34m + 4cm = 2.38cm. Repeat with another word problem to add a multiple of 10cm.
Group Activities
-- Convert distances in m to cm, or vice versa, to help solve measures problems.
-- Solving measurement problems, recognise which digit will change when a number of m or cm is added.

You Will Need

  • 100-bead bar and tags
  • 0.01–1 square (blank - see resources)
  • 0.01–1 square (completed - see resources)
  • Counting stick
  • Flipchart and pens
  • Whiteboards and pens
  • 0–9 dice and 1–6 dice
  • Counters
  • Snail journeys (see resources)
  • Measurement problems (see resources)

Mental/Oral Maths Starters

Suggested for Day 1
How many ml in a litre, mm in a cm, g in a kg? (simmering skills)

Day 2
Count up and down in steps of 0.01 through multiples of 0.1 and 1 (pre-requisite skills)

Day 3
Write lengths between 3m and 4m, then put in order (pre-requisite skills)


Day 1
Fill in missing numbers in rows and columns in a 0.01–1 square.
Fill in missing numbers on sections of the 0.01–1 square.

Day 2
Use a 0.01–1 square to help to add/subtract multiples of 0.01 and 0.1.
Add/subtract multiples of 0.01 and 0.1, first using the 0.01–1 square, then adding to/subtracting from numbers >1.

Day 3
Convert cm to metres; use in a problem-solving context.
Answer measurement word problems involving cm to metre conversions.

Mastery: Reasoning and Problem-Solving

  • Write the missing numbers in each sequence:
    4.55, 4.56, 4.57, ☐, ☐, ☐, ☐
    1.05, 1.04, 1.03, 1.02, ☐, ☐, ☐, ☐
    5.45, 5.46, 5.47, ☐, ☐, ☐, ☐
    9.56, 9.66, 9.76, ☐, ☐, ☐, ☐
  • Add 0.01 five times to each number.
    -- 4.87
    -- 3.07
    -- 7.98
  • The height of four trees is shown. Each tree grows 45cm. Write their new heights.
    (a) Poplar: 29.5m
    (b) Willow: 25.3m
    (c) Aspen: 11.6m
    (d) Cedar: 6.8m

In-depth Investigation: Decimals in a Row
Play a dice game on a 0.01–1 square, aiming to get four numbers in any row or column.

Extra Support

Tiny Hops
Counting on and back in 0.1s; adding/subtracting tenths, e.g. 1.8 + 0.4.