Year 7 Maths: Word Names for Decimal Numbers

Introduction

Understanding how to write and read decimal numbers in words is an essential skill in Key Stage 3 mathematics. Decimals are numbers that contain a whole number part and a fractional part, separated by a decimal point. Reading and writing decimal numbers accurately helps with comprehension in various maths topics such as money, measurements, and scientific data.

In this topic, we will explore how to correctly write decimals in word form and vice versa. By the end of this guide, you will be able to confidently translate decimal numbers into words and understand their value.

Writing Decimal Numbers in Words

Decimals are written as a combination of whole numbers and fractional parts. When writing a decimal in words, follow these steps:

1. Write the whole number part (if there is one) as you would normally write any number in words.
2. Use the word “point” to indicate the decimal point.
3. Read each digit after the decimal point individually (as separate digits).
4. Indicate the place value of the final digit (such as tenths, hundredths, thousandths, etc.) if needed.

Example

Take the number ( 23.456 ):

• The whole number is 23, which is written as “twenty-three.”
• The decimal point is written as “point.”
• The digits after the decimal point are read individually: 4, 5, and 6.

Thus, ( 23.456 ) is written as “twenty-three point four five six.”

Special Case: Decimal Numbers Less Than 1

If a decimal is less than one, start with “zero” before the decimal point.

For example, ( 0.72 ) is written as “zero point seven two.”

Writing Words as Decimal Numbers

Converting words back into decimal numbers involves the reverse process. Listen or read carefully to distinguish between whole numbers, the word “point” for the decimal point, and each digit after the point.

For example, the word “forty-six point two five” would be written as ( 46.25 ).

Practice Questions

Here, we provide three sets of questions (Easy, Medium, and Hard) to test your understanding of word names for decimal numbers.

Easy Level Questions (20 Questions)

Convert the following decimal numbers into words:

1. ( 1.5 )
2. ( 2.34 )
3. ( 0.78 )
4. ( 10.2 )
5. ( 7.06 )
6. ( 3.9 )
7. ( 12.5 )
8. ( 4.01 )
9. ( 6.3 )
10. ( 15.42 )
11. ( 0.6 )
12. ( 9.8 )
13. ( 1.07 )
14. ( 0.4 )
15. ( 5.22 )
16. ( 8.0 )
17. ( 13.6 )
18. ( 11.5 )
19. ( 2.1 )
20. ( 0.9 )

Medium Level Questions (20 Questions)

Convert the following decimal numbers into words:

1. ( 123.45 )
2. ( 76.982 )
3. ( 0.53 )
4. ( 456.789 )
5. ( 35.625 )
6. ( 89.12 )
7. ( 101.01 )
8. ( 67.890 )
9. ( 300.05 )
10. ( 99.99 )
11. ( 245.1 )
12. ( 14.56 )
13. ( 0.01 )
14. ( 88.77 )
15. ( 72.03 )
16. ( 6.666 )
17. ( 540.5 )
18. ( 32.123 )
19. ( 450.2 )
20. ( 100.004 )

Hard Level Questions (20 Questions)

Convert the following decimal numbers into words:

1. ( 1032.456 )
2. ( 987.654 )
3. ( 0.001 )
4. ( 1.00001 )
5. ( 54321.09876 )
6. ( 999.999 )
7. ( 0.0002 )
8. ( 10.505050 )
9. ( 654.321 )
10. ( 50.0005 )
11. ( 2048.128 )
12. ( 0.9999 )
13. ( 333.3333 )
14. ( 4567.89012 )
15. ( 3.14159 )
16. ( 25000.0001 )
17. ( 800.80808 )
18. ( 0.00001 )
19. ( 12345.6789 )
20. ( 75.0075 )

Answers and Explanations

Easy Level Answers

1. ( 1.5 ) – “one point five”
2. ( 2.34 ) – “two point three four”
3. ( 0.78 ) – “zero point seven eight”
4. ( 10.2 ) – “ten point two”
5. ( 7.06 ) – “seven point zero six”
6. ( 3.9 ) – “three point nine”
7. ( 12.5 ) – “twelve point five”
8. ( 4.01 ) – “four point zero one”
9. ( 6.3 ) – “six point three”
10. ( 15.42 ) – “fifteen point four two”
11. ( 0.6 ) – “zero point six”
12. ( 9.8 ) – “nine point eight”
13. ( 1.07 ) – “one point zero seven”
14. ( 0.4 ) – “zero point four”
15. ( 5.22 ) – “five point two two”
16. ( 8.0 ) – “eight point zero”
17. ( 13.6 ) – “thirteen point six”
18. ( 11.5 ) – “eleven point five”
19. ( 2.1 ) – “two point one”
20. ( 0.9 ) – “zero point nine”

Medium Level Answers

1. ( 123.45 ) – “one hundred twenty-three point four five”
2. ( 76.982 ) – “seventy-six point nine eight two”
3. ( 0.53 ) – “zero point five three”
4. ( 456.789 ) – “four hundred fifty-six point seven eight nine”
5. ( 35.625 ) – “thirty-five point six two five”
6. ( 89.12 ) – “eighty-nine point one two”
7. ( 101.01 ) – “one hundred one point zero one”
8. ( 67.890 ) – “sixty-seven point eight nine zero”
9. ( 300.05 ) – “three hundred point zero five”
10. ( 99.99 ) – “ninety-nine point nine nine”
11. ( 245.1 ) – “two hundred forty-five point one”
12. ( 14.56 ) – “fourteen point five six”
13. ( 0.01 ) – “zero point zero one”
14. ( 88.77 ) – “eighty-eight point seven seven”
15. ( 72.03 ) – “seventy-two point zero three”
16. ( 6.666 ) – “six point six six six”
17. ( 540.5 ) – “five hundred forty point five”
18. ( 32.123 ) – “thirty-two point one two three”
19. ( 450.2 ) – “four hundred fifty point two”
20. ( 100.004 ) – “one hundred point zero zero four”

Hard Level Answers

1. ( 1032.456 ) – “one thousand thirty-two point four five six”
2. ( 987.654 ) – “nine hundred eighty-seven point six five four”
3. ( 0.001 ) – “zero point zero zero one”
4. ( 1.00001 ) – “one point zero zero zero zero one”
5. ( 54321.09876 ) – “fifty-four thousand three hundred twenty-one point zero nine eight seven six”
6. ( 999.999 ) – “nine hundred ninety-nine point nine nine nine”
7. ( 0.0002 ) – “zero point zero zero zero two”
8. ( 10.505050 ) – “ten point five zero five zero five zero”
9. ( 654.321 ) – “six hundred fifty-four point three two one”
10. ( 50.0005 ) – “fifty point zero zero zero five”
11. ( 2048.128 ) – “two thousand forty-eight point one two eight”
12. ( 0.9999 ) – “zero point nine nine nine nine”
13. ( 333.3333 ) – “three hundred thirty-three point three three three three”
14. ( 4567.89012 ) – “four thousand five hundred sixty-seven point eight nine zero one two”
15. ( 3.14159 ) – “three point one four one five nine”
16. ( 25000.0001 ) – “twenty-five thousand point zero zero zero one”
17. ( 800.80808 ) – “eight hundred point eight zero eight zero eight”
18. ( 0.00001 ) – “zero point zero zero zero zero one”
19. ( 12345.6789 ) – “twelve thousand three hundred forty-five point six seven eight nine”
20. ( 75.0075 ) – “seventy-five point zero zero seven five”

This exercise covers a broad range of decimal numbers to develop fluency in reading, writing, and understanding decimal values. Practice regularly to improve your ability to convert between number forms and word names for decimal numbers.