In order to introduce decimals to children using the following method, they need to have had some previous experience of fractions (in particular tenths).
1) Draw a rectangle on the board and split it into ten sections. Ask a child how we can label each section of the rectangle (i.e. 1/10). Write 1/10 in each section…
| 1/10 | 1/10 | 1/10 | 1/10 | 1/10 | 1/10 | 1/10 | 1/10 | 1/10 | 1/10 |
2) Colour some of the rectangles, e.g.
| 1/10 | 1/10 | 1/10 | 1/10 | 1/10 | 1/10 | 1/10 | 1/10 | 1/10 | 1/10 |
3) Ask the children what fraction of the rectangle has been coloured (i.e. 1/10 + 1/10 + 1/10 = 3/10).
4) Explain that 3/10 can be written in another way… i.e. 0.3 (no units and three tenths)
5) Explain the features of the notation:
- The dot in between the 0 and the 3 is called the DECIMAL POINT and we use it to separate the units from the tenths.
- We always write in the 0 before the decimal point because it reminds us that the whole number is less than one.
- We say this number as “nought point three” or “zero point three”.
6) Now give each child a copy of the strips worksheet below. They should cut out a strip and colour some of the sections (and then stick it in their books). Next, they should write the following information into their books, changing the numbers according to the number of strips that they have coloured.
| 1/10 | 1/10 | 1/10 | 1/10 | 1/10 | 1/10 | 1/10 | 1/10 | 1/10 | 1/10 |
7/10 of the strip has been coloured.
7) Step 6 can be repeated with the children colouring different number so sections on new strips.
