You have already seen ratio bars used to describe a split, like two parts juice to three parts water. Today we go one step further and actually share out a real amount.

Here is the question: share €30 between two people in the ratio 2:3. Before we work anything out, how many equal parts do you think €30 needs to be split into?

Look at four finished shares on the ratio bars, one after another. For each one the teacher talks through the same three moves in order: count all the parts, divide the total by that count to find one part, then multiply to find each share. Notice how the moves stay the same even as the ratios change.

• Count: add the parts of the ratio
• Divide: total ÷ part-count = value of one part
• Multiply: each person's parts × value of one part

Now we build the shares together on the ratio bars. We work through these one at a time at the board as a class: share €60 in 1:5, then €72 in 3:5, then €50 in 2:3, and finally the three-way €120 in 1:2:3.

One pupil sets each share at the board while everyone else watches, agrees, or corrects out loud — that is your job at each round. For every problem we say the three moves aloud before we set the bars: count the parts, divide the total, multiply each share. The three-way one at the end has six parts, so the value of one part is smaller than you might guess, watch for it.

Now we work through some shares: first €80 in 3:5, then €72 in 3:5, then €100 in 2:3, and finally the three-way €120 in 1:2:3. Before each one is checked, put a hand up with your prediction of the value of one part. A wrong prediction is completely fine — guessing first and then checking is exactly how we spot our own slips.