# Castle Douglas Primary and Early Learning and Childcare Centre # Decimals and Percentages

Activity 1 – Whose is Greater?

Focus – I can compare and order decimals showing tenths and hundredths.

Resources – pencil and paper.

Write a range of decimals onto small pieces of paper or card, e.g. 1·4 and 0·75. Then play a game with another family member or friend. Each picks a card. The player with the larger decimal keeps both cards. If you like you can also record the decimals as number statements e.g. 0·3 > 0·28. Activity 2 – Decimal Ordering.

Focus – I can compare and order decimals showing tenths and hundredths.

Resources – pencil and paper.

Use the same cards from Activity 1. (Write a range of decimals onto small pieces of paper or card, e.g. 1·4 and 0·75.) Pick sets of five cards and order them. You could also include extra cards where they write the decimals in words, e.g. six point three or zero point seven five. Activity 3 – True Statements 1

Focus – I can multiply decimal numbers by 10, 100 or 1000.

Resources – pencil and paper.

Make the following cards: 3, ·, 5, ×, 1, 10, 100, 1000, 0, =.

Then choose cards and arrange them in as many different ways as you can to make true statements. Cards can be used more than once in each statement, e.g. 5·03 × 10 = 50·3. Activity 4 – My Height.

Focus – I can multiply decimal numbers by 10, 100 or 1000.

Resources – pencil and paper.

Write your height in metres. Then record your height in centimetres (by multiplying by 100), and in millimetres (by multiplying by 1000). Do the same with the heights of other family members. Activity 5 – True Statements 2

Focus – I can divide numbers by 10, 100 or 1000 which create decimal answers.

Resources – pencil and paper.

Make the following cards: 3, ·, 5, ÷, 1, 10, 100, 1000, 0, =.

Then choose cards and arrange them in as many different ways as you can to make true statements. Cards can be used more than once in each statement, e.g. 5·3 ÷ 10 = 0·53. Activity 6 – Percentage Search.

Focus – I can explain what a percentage is and how it relates to fractions and decimals.

Resources – household items, pencil and paper.

Look around the house for items, food or clothing labels or newspaper or magazine cuttings that involve percentages, e.g. 10% less fat, 95% cotton, and write the percentages as decimals and as fractions in their simplest form, e.g. 95% = 19/20 = 0∙95. Activity 7 – Pattern Colouring Squared Paper.

Focus – I can explain what a percentage is and how it relates to fractions and decimals.

Resources – Squared Paper (from school) and coloured pens.

Use squared to make a 10×10 square. Colour the paper using up to five colours to make a pattern. You should only colour whole squares. Then  write statements about what fraction, decimal and percentage of your pattern is each colour, e.g. 0∙25, 25/100 and 25% of this pattern is red. Activity 8 – Puzzle time.

Focus – I can find a simple percentage of an amount using my knowledge of fractions.

Resources – pencil and paper

Have a go at solving this puzzle.
A farmer has 180 animals in a field. 1/5 are sheep, 25% are cows, 5% are horses and the rest are pigs. What percentage are pigs? How many of each animal?

Have a go at writing your own puzzle for others to solve and email it to gw08officecastle@ea.dumgal.sch.uk Activity 9 – Mix and Match.

Focus – I can add and subtract decimals using my mental strategies and written methods – Tenths.

Resources – pencil and paper.

Copy these decimals: 5·9, 3·1, 8·8, 26·9, 17·7, 36·8 and 40·6. Choose pairs of the numbers and find the totals and differences, using appropriate mental or written methods. Which pair of numbers has a total closest to 45? Activity 10 – Decimal Digits.

Focus – I can add and subtract decimals using my mental strategies and written methods – Tenths and hundredths.

Resources – pencil and paper

Try to make as many 3-digit decimals as you can using the digits 5, 8 and 3, e.g. 5·38, 35·8, 8·35. Then find sums and differences of the numbers, using appropriate mental or written methods. Challenge – what is the largest/smallest possible answers. Activity 11 – Which is Largest – Multiplying?

Focus – I can multiply decimals by a single digit using my mental strategies and written methods – Tenths and Hundredths.

Resources – pencil and paper

Work out which of the following four calculations has the largest answer: 3·51 × 6

2·25 × 9

2·89 × 7

3·89 × 5

Predict first and then use an appropriate written or mental method to perform each calculation. Activity 12 – Which is Largest – Dividing?
Focus – I can divide decimals by a single digit using my mental strategies and written methods – Tenths.

Resources – pencil and paper

Work out which of the following four calculations has the largest answer: 5·4 ÷ 6

3·5 ÷ 5

3·2 ÷ 4

8·1 ÷ 9

Predict first and then use a mental or expanded method to perform each calculation. Activity 13 – True or False?

Focus – I can solve problems involving percentages – Find a percentage of an amount.

Resources – pencil and paper

1. 5% of 800 is less than 1% of 5000
2. 7% of 600 is greater than 80% of 20
3. 15% of 400 is greater than 10% of 810
4. 50% of 2010 is the same as 75% of 1340
5. 60% of 640 is less than 30% of 920
6. 25% of 76 is greater than 75% of 50
7. 40% of 450 is less than 60% of 560
8. 45% of 60 is the same as 80% of 35 Activity 14 – Check it Out.

Focus – I can solve problems involving percentages – Increase or decrease by a percentage.

Resources – pencil and paper

Explore the order of percentage changes in a question and determine whether they produce the same answer,
e.g. to find out whether a 50% increase followed by a 10% decrease is the same as a 10% decrease followed by a 50% increase. Activity 15 – Badges Squared Paper.

Focus – I can solve problems involving percentages – Work out a percentage.

Resources – coloured pens and squared paper (from school)

Draw some badges on to squared paper that are made from 10, 20, 25 or 50 small squares. For each badge, colour the badge using different colours and then write statements about what percentage of each badge is each colour, e.g. 4 out of 25 squares are red so 16% of the badge is red. Sheep = 36    Cows = 45     Horses = 9    Pigs = 90

1. 40 < 50 TRUE
2. 42 > 16 FALSE
3. 60 > 81  FALSE
4. 1005 = 1005 TRUE
5. 384 < 276 FALSE
6. 19 > 36  FALSE
7. 180 < 336 TRUE
8. 27 = 28 FALSE