Look at the three groups of blocks in the picture on the board, labelled A, B and C. Up to now, a flat meant one hundred, a rod meant ten and a small cube meant one. Today we are going to relabel them: the flat is now 1, the rod is now 0.1 and the small cube is now 0.01. Read each group as a decimal. What number is group A showing? What about B and C?

Each interactive shows a decimal made from blocks in the units, tenths and hundredths columns. Notice which columns have blocks and which are empty, and read the number.

Let's try a few together. When I call out a decimal, build it on the place-value mat with the U, t and h columns. The numbers we will work through are 0.6, 0.43, 0.08 and 1.04. We will read each one aloud as a class and check the columns before we move on.

Today we work through these numbers together: 0.06, 0.4, 0.43, 1.07 and 2.5. The zeros catch people out, so we will say each one aloud and check the columns before we press Check.

What we learned today

• We relabelled the blocks: a flat is 1, a rod is 0.1, a small cube is 0.01.
• The first column after the decimal point is tenths, the second is hundredths.
• A zero in a decimal holds a place — in 1.05 the zero keeps the 5 in the hundredths column.

Coming up

Next we will put decimals onto a number line, so we can see exactly where a number like 0.7 or 0.34 sits between two whole numbers.