Display the timetable image as pupils settle. Give five seconds of quiet think-time, then take two or three hands-up answers — do not confirm which is right yet, that lands in the next step.

Listen for the common slip: subtracting 09 minus 07 to get 2 hours and stopping there. Hold that thought; the 35 minutes is what the lesson works on.

Point at the depart cell, then the arrive cell, for each journey. Say the count-up aloud so pupils hear the bridging: 07:00 to 08:00 is one hour, 08:00 to 09:00 is two hours, then 09:00 to 09:35 is thirty-five minutes.

• 07:00 to 09:35 — a clean two-hour-plus-minutes journey; the one to model most carefully.
• 09:00 to 11:35 — same shape, later in the day; ask the class to predict the time before you count it.
• 12:15 Thurles to 12:50 Portlaoise — a short hop that stays inside one hour, so the answer is just the minutes: 12:15 to 12:50 is thirty-five minutes.

Do not proceed until the class can say the count-up steps back to you.

Talk this one through together — pupils take turns at the board and the class agrees or corrects out loud. Model the bridging count-up on the first two. On Thurles to Portlaoise, remind the class there is no whole hour to bridge, so the answer is just the minutes.

Ask a pupil to tap depart first, then arrive; the class calls out the count-up before the interactive confirms the elapsed time. Revoice a strong answer. So you went up to the next whole hour first. Then you counted the hours. Then you added the last minutes.

Watch for pupils reading the wrong column — the depart cell and arrive cell must sit in the same service column, or the journey doesn't exist. If two cells are in different columns, ask could you catch that same train?

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.

Before each Check, the class predicts the elapsed time from the count-up. On a wrong cell, ask are both cells in the same service column? The last challenge is the notice-and-compare moment: the 11:00 Cork-to-Heuston is 2 hours 35 minutes, exactly the same as the 07:00 service, so a later start does not make the journey longer.