Short Blocks

# Maths Year 6 Autumn Decimals and Fractions (A)

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

## Unit 1 Add or subtract decimals (suggested as 3 days)

### Planning and Activities

Day 1 Teaching
Use counting stick to count in 0.01s from 2.45 to 2.55 and back. Label 2.5 with a Post-it. Write 2.52 – 0.03. Count back from 2.52 to 2.49. Sketch a jotting to show how we ‘bridge’ 2.5. Repeat for 2.47 + 0.07. Mark the centre as 2, then count in 0.01s from 1.95 to 2.05 and back. Use the counting stick and a jotting to work out 2.02 – 0.05.
Group Activities
-- Game to add and subtract multiples of 0.01 crossing through multiples of 1 and 0.1 using a number line.
-- Repeatedly add 0.06, then subtract 0.07. Challenge to repeatedly add multiples of 0.01 to end on a given number.

Day 2 Teaching
Show 3 DVDs labelled £10.49, £14.79, £12.25. Estimate total cost by rounding. Model compact addition to find total cost. Remind children to leave a line below numbers being added so we can write extra digits. Finish and compare with estimate. Repeat for 3 other prices.
Group Activities
-- Add three amounts of money, aligning digits correctly. Estimate totals first.
-- Add two amounts of money, aligning digits correctly. Estimate totals first.
Write three amounts with a total within a given range.

Day 3 Teaching
Use the distance that snails crawl to generate decimal additions. Children round each distance to nearest metre to estimate the total. Model column addition, showing how to align decimal points.
Group Activities
Use the ‘Adapt Four of the Best’ in-depth problem-solving investigation below as today’s group activity.
Or, use these activities:
-- Add and round three distances in metres (2dp) crawled by snails.
-- Shuffle given digit cards to make additions of distances in metres with 2dp, round and find the total.

### You Will Need

• Counting stick
• Post-it notes
• Decimal number lines (see resources)
• 1 to 6 dice
• Three DVDs with price labels £10.49, £14.79 and £12.25
• Whole class practice sheet (see resources)
• Flipchart and pens
• Digit cards
• Mini-whiteboards and pens

### Mental/Oral Maths Starters

Day 1
Count on in steps of 0.01 and 0.1 (pre-requisite skills)

Suggested for Day 2
Double numbers with 1 decimal place (simmering skills)

or
Halve numbers with 1 decimal place (simmering skills)

Day 3
Round numbers with 2dp to the nearest 1 and 0.1 (pre-requisite skills)

### Worksheets

Day 1
Add and subtract multiples of 0.01, crossing through multiples of 1 and 0.1 including word problems and using a number line.

Day 2
Practise using column addition to add two then three amounts of money.

Day 3

### Mastery: Reasoning and Problem-Solving

• Jo counts from a number to 4.5 in eleven steps of 0.03. What was her starting number?
• Write the next 4 numbers in each sequence:
2.68, 2.69, __, __, __, __
6.43, 6.42, __, __, __, __
1.98, 1.99, __, __, __, __
• Write the missing numbers:
3.24 + 0.04 = ☐
☐ + 0.07 = 3.5
4.56 + ☐ = 4.76
• Jim runs 13.85 kilometres and Ann runs 12.78 kilometres to meet him. How far have they run in total?

In-depth Investigation: Adapt Four of the Best
Adapt the numbers in the top row and left column to use two-place decimals, e.g. 1.27, 5.09 etc.

### Extra Support

All the 3s
Understanding place value in numbers with two identical places; Adding and subtracting multiples of 0.1 and 0.01 (not crossing 1s or 0.1s)

Take Away Night

## Unit 2 Subtract 1- and 2-place decimals (suggested as 2 days)

### Planning and Activities

Day 1 Teaching
Write 10 – 6.47. Draft an empty number line (ENL) jotting to show a hop from 6.47 to 6.5 then to 7 or one hop straight from 6.47 to 7. Then show a hop from 7 to 10. Children show how to do 9 – 8.63. Then 2.85m + ? = 3.18m and 1.83m + ? = 2.2m.
Group Activities
-- Discuss when to use column subtraction and when Frog (counting up) is preferable when subtracting numbers with one or two decimal places.
-- Spot that given subtractions have the same answer, discuss why and write other pairs of numbers with the same difference.
--Focus on adding hops correctly when using Frog (counting up).

Day 2 Teaching
Write 4.2 – 2.57. Draft an empty number line to show a hop from 2.57 to 3 then to 4.2. Children show how to do 6.5 – 4.78. Then 6.5 – 4.38 and 4.27 – 3.8. Discuss how it is important to add the correct digits together.
Group Activities
Use the ‘Dicey Difference’ in-depth problem-solving investigation below as today’s group activity.
Or, use these activities:
-- Investigate subtracting numbers with consecutive digits, 9.8 – 7.65, 8.7 – 6.54, 7.6 – 5.43 …

### You Will Need

• Mini-whiteboards and pens
• Flipchart and pens
• Bamboos growing rate sheet (see resources)

### Mental/Oral Maths Starters

Day 1
Pairs of numbers with 1 decimal place and a total of 10 (pre-requisite skills)

or
Say how much is needed to the next metre (pre-requisite skills)

Day 2
Complements to the next whole (pre-requisite skills)

### Worksheets

Day 1
Work out how much bamboo grows each day.
Calculate differences in athletics results.

Day 2
Choose how to subtract numbers with one or two decimals places.

### Mastery: Reasoning and Problem-Solving

• Write the missing number in the bar diagram:
 4.06 2.68 ?
• Write two 2-place decimal numbers which add to 6. Write two different 2-place decimal numbers which add to 4.5.
• Frog counts up from a number, finishing on 3.4. He makes 3 jumps: first 0.23, then 1, then 0.4. Write the subtraction he is solving.
• Calculate 7 – 2.89 mentally without writing anything. Check your answer using Frog.

In-depth Investigation: Dicey Differences
Children use two dice with decimal numbers to find largest and smallest possible differences, and use mathematical reasoning to calculate the probability of getting close to a specified target.

### Extra Support

Counting up (using Frog) from numbers with two decimal places to the next whole number

## Unit 3 Understand decimals with three places (suggested as 3 days)

### Planning and Activities

Day 1 Teaching
Display a place value chart with 10s, 1s, 0.1s, 0.01s and 0.001s. Point at 0.001s; these are 1/1000s. Ring a number on each row. Children write total. Repeat. Use a PV grid 100s, 10s, 1s, 0.1s, 0.01s, 0.001s. Model × and ÷ by 10 and 100.
Group Activities
-- Write place value additions, multiply and divide by 10 and 100 (to include numbers/answers with up to 3 decimal places). (Includes pre-teaching for Day 2.)
-- Play I’m thinking of a number with place value additions/subtractions (numbers with 3 decimal places).

Day 2 Teaching
Give 4 children cards, e.g. 1, 2, 3 and 4. They stand either side of a large decimal point on the flipchart to show 1.234. Ask them to multiply the number by 10 and move accordingly. Repeat to ×/ ÷ by 10, 100 and 1000. Repeat for 4567.
Group Activities
Use the ‘Crack the Code’ in-depth problem-solving investigation below as today’s group activity.
Or, use these activities:
- -Choose a function machine (× 10, ÷ 10, × 100, ÷ 100, × 1000 or ÷ 1000), write the output, partner guesses the input.
-- Select a card with multiplication or division to show on place value grid (× 10, ÷ 10, × 100, ÷ 100, × 1000 or ÷ 1000). Partner guesses the calculation on the card.

Day 3 Teaching
Show a 0–0.1 landmarked line. Use this to place numbers with 3 decimal places on lines; round to the nearest 0.01, 0.1 or 1; Compare 2 numbers using the line.
Group Activities
Order numbers with 3 decimal places, check by placing on landmarked lines.
-- Write numbers in given ranges, order, place on lines and round to the nearest whole and tenth.

### You Will Need

• Place value chart (see resources)
• Place value grid (see resources)
• Large number cards (0–9)
• Additional activity sheets (see resources)
• 0 to 9 digit cards (with extra 0s)
• Landmarked lines
• A 3 to 4 & a 7 to 8 number line

### Mental/Oral Maths Starters

Suggested for Day 1
Count in steps of 0.01 and 0.1 through multiples of 0.1 and 1 (simmering skills)

Day 2
Place numbers with 2 decimal places on a line (pre-requisite skills)

Day 3
Round numbers with 2 decimal places to the nearest 1 and 0.1 (pre-requisite skills)

### Worksheets

Day 1

Day 2
Work out the outputs, for × 10, ÷ 10, × 100, ÷ 100, × 1000 and ÷ 1000 function machines.

Day 3
Place numbers with 3 decimal places on lines, then solve ‘Who am I?’ puzzles.
Place numbers with 3 decimal places on lines, then round to the nearest hundredth, tenth and whole.

### Mastery: Reasoning and Problem-Solving

• How many times must I add 0.001 to 2.251 to reach 2.27?
How many times must I add 0.001 to 9.99 to reach 10?
• Draw a line from 9.99 to 10. Mark 9.995 and two other numbers, one more than 9.995 and one less.
• Write the missing numbers in these sentences.
4.351 × 10 = ☐
☐ × 100 = 39.2
1.871 × ☐ = 1871
• Write <, = or > between each pair of numbers.
3.405 3.45
8.06 8.061
9.219 9.201
0.002 2/1000

In-depth Investigation: Crack the Code
Children use logical thinking and number bonds to solve a mathematical puzzle involving multiplying by 10 and 100 and adding decimal numbers.

### Extra Support

Dastardly Decimals
Understanding place value in numbers with two decimal places

## Unit 4 Add/subtract multiples of 0.1, 0.01, 0.001 (suggested as 2 days)

### Planning and Activities

Day 1 Teaching
Show a partially completed 0.001 to 0.1 grid. Count in 0.001s to 0.01. What’s next? Complete 2nd row. What do we add to move down a square? Fill in one column. Children discuss what number is in bottom right-hand corner. Count to check.
Group Activities
-- Use counting in steps of 0.001 and 0.01 to complete rows and columns in a partially complete 0.001 to 0.1 number grid.
-- Use counting in steps of 0.001 and 0.01 to write numbers in various places in a partially complete 0.001 to 0.1 number grid.

Day 2 Teaching
Start with 34.567. Add or subtract multiples of 10, 1, 0.1, 0.01, 0.001, making sure we do not count through a multiple of 0.1 or 1, e.g. not 34.67 + 0.05 or 34.23 – 0.4. Are children changing the correct digit each time? Re-write 34.567. Together, add 0.005 counting on in 0.001s, taking care when crossing 34.57.
Group Activities
Use the in-depth problem-solving investigation ‘Sometimes We Lose Things’ from NRICH as today’s group activity.
Or, use these activities:
-- Add and subtract multiples of 0.1, 0.01 or 0.001, focusing on passing through multiples of 0.01.
-- Use a counting stick to support counting on and back steps of 0.001.
-- Repeatedly add 0.007, 0.07 and 0.7 to pass targets, predicting how many of each need to be added.

### You Will Need

• Partially completed 0.001 to 0.1 grid (see resources)
• Mini-whiteboards & pens
• Add & subtract multiples of 0.1, 0.01 or 0.001 sheet (see resources)
• Flipchart and pens
• Counting stick
• Post-it notes

### Mental/Oral Maths Starters

Day 1
Place value in numbers with 3 decimal places (pre-requisite skills)

Suggested for Day 2
Convert from m to cm, cm to mm and vice versa (simmering skills)

### Worksheets

Day 1
Fill in sections from a 0.001 to 0.01 number grid.
Use a 0.001 to 0.01 grid to add and subtract 0.001 and 0.01.

Day 2
Add and subtract multiples of 0.1, 0.01 or 0.001.

### Mastery: Reasoning and Problem-Solving

• Write the missing numbers to complete this section of the 0.001 to 0.1 grid
 0.047 0.048 0.049 0.068 0.079 0.087
• What must be added to 0.089 to make 0.09?
To make 0.9?
• True or false?
3.452 – 0.003 = 3.449
0.002 + 1.009 = 1.11
2.985 + 0.005 = 2.99
0.019 > 0.091

In-depth Investigation: Sometimes We Lose Things
What would happen if we lost all the nines in our number system? Children's understanding of the place value system is put to the test. Sometimes We Lose Things from nrich.maths.org.

### Extra Support

All the 3s
Understanding place value in numbers with two identical places; Adding and subtracting multiples of 0.1 and 0.01 (not crossing 1s or 0.1s)