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Send the course name, exam board or awarding body, specification code and exam year if relevant. These details help distinguish a gap in subject knowledge from a mismatch between the practice material and the assessment. The examples below refer to named GCSE and A-level qualifications; they are not a single syllabus for every UK learner.

Suppose a practice task asks a learner to count scores of 50 or more. This constructed Python example uses selection (the if decision) inside iteration (the loop):

scores = [49, 50, 72]
passed = 0
for score in scores:
    if score >= 50:
        passed = passed + 1
print(passed)

Trace one score at a time. At 49, the condition is false and passed stays 0. At 50, it is true and the count becomes 1. At 72, it is true again and the count becomes 2. The program prints 2.

If the learner writes score > 50, the program still runs, but prints 1: it excludes exactly 50. That is a logic error, not a syntax error. The correction is >=, meaning “greater than or equal to”. A stronger explanation is: “50 meets the task’s minimum, so it must be counted.”

For follow-up practice, use [50, 50, 49]. The correct output is 2; ask the learner to predict it before running the code. This checks the boundary again with changed data, rather than relying on a memorised answer. It illustrates the tracing and error-correction skills included in OCR J277; Python is the language used for this example.

Take the sorted list [3, 8, 12, 17, 25, 31, 40] and search for 25. Inspect the middle value, 17. Because the list is in ascending order and 25 is greater than 17, discard 17 and everything to its left. The remaining list is [25, 31, 40]. Its middle value is 31, so discard 31 and everything to its right. The remaining value is 25: found after three inspections.

The key explanation is the reason for discarding half the possibilities. “Binary search starts in the middle” describes an action. “The list is sorted, so the target cannot be in the half being discarded” explains why that action is valid. On an unsorted list, that reasoning fails.

AQA 7517 includes the comparison between linear search, with worst-case time complexity O(n), and binary search, with O(log n). Here n is the number of items; the notation describes how work grows as the list gets larger. Linear search may inspect every item, while binary search repeatedly halves the remaining possibilities. The three inspections above illustrate one search, not a fixed time for every input.

For practice, search the same list for 26. The inspections are again 17, 31 and 25, but 26 is not equal to any of them and no positions remain to search. Ask the learner to explain that “not found” result using the sorted order.

A useful starting task is small enough for the learner to explain aloud. Bring an attempted question or a short piece of practice code, including the expected result and what actually happened. This gives the tutor something concrete to discuss.

Latimer’s service is online first. Microsoft Teams is the default lesson platform, and you and the tutor can agree another option. For a coding lesson, also agree the programming language, version and editor so time is not spent solving an avoidable setup mismatch.

Have the task, a copy of the practice code and any error message ready. Check that the tutor can read the shared code and that the learner can type and run it. Use dummy information in examples and shared files; keep passwords and private account details out of shared work. On a school-managed device, check installation restrictions before adding software and ask about an approved option if needed.

For theory work, a short written answer, a diagram or a trace table may be more useful than opening an editor. Let the learning task determine the setup.