Decimals

For grown-ups: this lesson in words

Years 4 to 6 · Maths

Decimals: I can read, compare and round decimals with tenths, hundredths and thousandths.

1. Here is a bar cut into 10 equal parts.

   3 of the parts are shaded. 3 out of 10 equal parts is 3 tenths.

   We can write 3 tenths as a decimal: 0.3. The dot is called the decimal point.

   Picture: A bar cut into 10 equal parts, with 3 parts shaded. It is labelled 0.3.

2. Here is 0.3 in a place value chart. It has 0 ones and 3 tenths.

   The decimal point sits between the ones and the tenths.

   The tenths column is the first place after the decimal point.

   Picture: A place value chart showing 0.3: 0 ones and 3 tenths. The tenths column is highlighted.

3. Here is 1 tenth as a place value counter: 0.1.

   Exchange it: 1 tenth is the same as 10 hundredths.

   So a hundredth is a tenth split into 10 equal parts. 10 hundredths make 1 tenth.

   One of those hundredth counters is 1 hundredth. We write it as 0.01.

   Picture: Place value counters with 0 ones, 1 tenth and 0 hundredths. One tenth is exchanged for 10 hundredths, making 0 ones, 0 tenths and 10 hundredths, still 0.1.

4. The next column is hundredths, two places after the decimal point.

   Here is 0.07: 0 ones, 0 tenths and 7 hundredths.

   The 0 in the tenths column holds the place. Without it, the 7 would slip into the tenths.

   Picture: A place value chart showing 0.07: 0 ones, 0 tenths and 7 hundredths. The hundredths column is highlighted.

5. Your turn: This bar is cut into 10 equal parts, and 7 parts are shaded. Which decimal shows the shaded part?

   Picture: A bar cut into 10 equal parts, with 7 parts shaded.

   Choose one:

   • 0.07
   • 0.7
   • 7

   Answer