Take two or three hands-up answers. Do not confirm yet, this is the puzzle the lesson opens.

Listen for the mistake of counting 3 footballs = 3 goals. Revoice a good answer: so one football is worth ten, so three footballs is thirty.

• Key of 2: 4 symbols. Ask for the total before you point at it (4 × 2).
• Key of 5: 3 symbols. Count 5, 10, 15 aloud with the class.
• Key of 10 with a half: hold out for the half. Ask what is half of ten? before revealing 25.

The move to draw out: read the key first, every time. Do not proceed until the class can say what one symbol is worth on each.

Talk this one through together, pupils take turns at the board and the class agrees or corrects out loud.

The builder opens empty. You re-label the three rows and enter the data live for each dataset in turn: first the medals (three teams, biggest value 20, key of 5), then clear it and enter the points (biggest value 30, key of 10), then the single row of 25 on a key of 10 to show the half symbol. The 'Team 1/2/3' labels in the tool are just a starting point, rename them to the teams the class chooses.

For each set, ask the class which key to pick before anyone places a symbol: if the biggest number is 20, is a key of 1 sensible, or would that be a very long row? Watch for pupils placing the right count of symbols but forgetting the key when they read the total back.

This is the practice round, pupils take turns at the board, check each answer, and the class confirms before moving on. Keep the board work brisk rather than over-explaining.

Read the key aloud before each round. The last two rounds are the stretch: totalling across rows needs every row read correctly first, and the comparison needs two totals held in mind. If a round runs quick, pose a follow-up question to the whole class or turn-and-name a pupil to explain their reasoning.