Decimals Games for Kids

Decimals are fractions written in place-value form, and they are all around us in money, measurements and sports scores. Maths Guru helps children compare, round and calculate with decimals, building from tenths up to thousandths.

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What decimals really mean

A decimal extends our place-value system to the right of the decimal point. After the ones column come tenths, then hundredths, then thousandths. So in 4.375 the 3 is worth 3 tenths (0.3), the 7 is 7 hundredths (0.07) and the 5 is 5 thousandths (0.005).

Each place is ten times smaller than the one on its left, which is why multiplying by 10 moves every digit one place to the left, and dividing by 10 moves it one place to the right. The decimal point does not move; the digits do.

Money is the most familiar example. Rs 12.50 is twelve rupees and fifty paise, and 0.5 is half. Linking decimals to measurements such as 1.5 litres or 2.25 metres gives children a firm sense of what the numbers represent.

Common mistakes to watch for

The biggest trap is thinking that a longer decimal is a bigger one. Children compare 0.45 and 0.5 and decide 0.45 is larger because 45 is more than 5. Writing 0.5 as 0.50 shows that 0.50 is more than 0.45. Lining up the decimal points and padding with zeros fixes this.

Another is treating the digits either side of the point as two separate whole numbers. That leads to errors such as 2.3 + 1.9 = 3.12 instead of 4.2, or a belief that 0.08 is larger than 0.8 because "eight" looks bigger than "zero point eight".

When multiplying by 10 or 100, children may "add a zero", which works for whole numbers but gives 0.3 × 10 = 0.30, which is wrong. The correct answer is 3. Teaching it as digits moving places avoids this trap.

How to practise at home

Use money. Ask your child to add the prices on a shopping bill with decimals, or work out which of two prices is cheaper. Measuring ingredients, heights and distances provides further practice with real decimals.

A place-value chart with columns for ones, tenths and hundredths helps. Have your child write a number like 3.84 in the chart and say each digit's value aloud. Then multiply by 10 and watch the digits move.

Estimate before calculating: 3.9 + 4.1 is about 8. Rounding is a useful skill in itself, since 4.76 rounds to 4.8 to one decimal place and to 5 as a whole number. Practising rounding in daily situations, like rounding a bill to the nearest rupee, makes it stick.

How Maths Guru teaches decimals

The Merchant's Scale in Conquer the World is the decimals island, and opens for the Year 3 to 4 group and above (ages 7 to 9 and older). Questions cover comparing decimals ("which is greater, 0.45 or 0.5?"), rounding to one decimal place or to the nearest whole number, multiplying and dividing by 10, 100 and 1000, and place-value questions such as "what is the value of the 7 in 4.375?"

The harder levels stretch to thousandths. Decimal addition and subtraction also appear in the fractions island, and Classroom quizzes let a teacher choose decimals as the live topic. Estimation Olympics and Shop Street build the number sense that makes decimals easier to place on a number line.

Worked examples

0.37 × 100

Answer: 37

Multiplying by 100 moves each digit two places left: 0.37 becomes 37.

5.1 × 10

Answer: 51

Each digit moves one place to the left, so 5.1 becomes 51.

36 ÷ 10

Answer: 3.6

Dividing by 10 moves each digit one place to the right, so 36 becomes 3.6.

123 ÷ 100

Answer: 1.23

Dividing by 100 moves each digit two places to the right, so 123 becomes 1.23.

2.7 + 1.5

Answer: 4.2

Add the tenths: 7 + 5 = 12 tenths, which is 1 whole and 2 tenths. Then 2 + 1 + 1 = 4 wholes, so 4.2.

3.84 − 1.2

Answer: 2.64

Write 1.2 as 1.20 so the places line up. Then 3.84 − 1.20 = 2.64.

Tips for parents

Always line up the decimal points when adding or subtracting.
Add zeros to compare: 0.5 is 0.50, so it is bigger than 0.45.
Describe multiplying by 10 as digits moving left, never as adding a zero.
Use money and measuring jugs to make decimals real.
Say numbers aloud properly: 0.45 is "zero point four five" or "forty-five hundredths".

Practise it in these games

Questions parents ask

When do children learn decimals?

Tenths are introduced at about ages 8 to 9 (Class 4, Year 4), and hundredths and rounding follow. In Maths Guru the decimals island is in the Year 3 to 4 group and above.

How do decimals relate to fractions?

Every decimal is a fraction with a denominator of 10, 100 or 1000: 0.7 = 7/10 and 0.25 = 25/100 = 1/4. Maths Guru's fractions levels include conversions in both directions.

Why is 0.5 larger than 0.45?

Because 0.5 is 5 tenths, which equals 50 hundredths, and 50 hundredths is more than 45 hundredths. Padding with a zero (0.50) makes the comparison visible.

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