Look at this fruit bowl: there are 4 apples and 6 oranges. How could you describe how many apples there are compared to how many oranges? Could you say it in one short way, instead of counting them all out every time?

Each pair of bars compares red counters with blue. Watch how we say the comparison in words, then how we write it with a colon. Listen for the colon standing in for one small word.

Let's try this together. When I call out a comparison, build the two bars, then read the ratio aloud as 'for every ___ there are ___'. For example, 'five boys to three girls' becomes two bars and the ratio 5 : 3, which we read as 'for every five boys there are three girls'. Remember, 'five to three' and 'for every five there are three' describe the very same comparison.

Today we work through these builds together at the board: make 2 : 5, then 3 : 4, then 7 : 2, and finally make 3 : 6. Read each one aloud as you check it.

Today's key ideas

• A ratio compares two amounts and is written with a colon, like 4 : 6.
• We read a ratio aloud as 'for every this, that many of those'.
• The order matters: 2 : 3 is not the same as 3 : 2.

Coming up

Next we will look at how ratios can be made simpler or scaled up, just like equivalent fractions, so that 4 : 6 and 2 : 3 can be seen as the same comparison.