RemeliaMaths Year 6 Fractions, decimals & %
Year 6 decimals multiplied and divided by 10, 100 and 1,000
The objective: Identify the value of each digit to 3 d.p.; multiply and divide by 10, 100, 1,000 giving answers to 3 d.p..
The explanation, example and questions are the ones Remelia uses in the app; the questions are not taken from any test paper.
The idea
Multiplying and dividing decimals by 10, 100 and 1000 moves the digits, exactly as with whole numbers.
How to do it
- × 10 moves every digit one column left; ÷ 10 one column right.
- Count the zeros to know how many columns.
- Fill empty columns with 0.
A worked example
2.4 ÷ 100 = 0.024, and 0.375 × 1000 = 375.
Watch for
Answers that gain or lose a place. Check: dividing should make it smaller.
Try four questions
-
Work out 6.473 × 100.
Show the answer to question 1
Answer: 647.3
Why:
Move every digit 2 places to the left: 6.473 × 100 = 647.3.
-
Work out 229 ÷ 100.
Show the answer to question 2
Answer: 2.29
Why:
Move every digit 2 places to the right: 229 ÷ 100 = 2.29.
-
Work out 8,942 ÷ 1,000.
Show the answer to question 3
Answer: 8.942
Why:
Move every digit 3 places to the right: 8,942 ÷ 1,000 = 8.942.
-
In 2.875, what is the value of the digit 7?
Write it as a decimal.
- A 0.17
- B 0.007
- C 0.7
- D 0.07
Show the answer to question 4
Answer: D · 0.07
Why:
The 7 is in the hundredths column, so it is worth 7 hundredths: 0.07.
Answers
- 1. 647.3
- 2. 2.29
- 3. 8.942
- 4. D · 0.07
The mistakes Remelia names
When a wrong answer to a question like these matches one of these mistakes, the app says what the child seems to have done before they try again.
- Question 1, the answer 6,473: Your digits are right, but in the wrong columns: your answer is 10 times too big.
- Question 1, the answer 64.73: Your digits are right, but in the wrong columns: your answer is 10 times too small.
- Question 4, the answer 7: That is the digit, not its value. A digit’s value is the digit multiplied by the column it sits in.
- Question 4, the answer C · 0.7: That digit is in a different column. After the decimal point come tenths, then hundredths, then thousandths.