Let students pick their challenge level, not their topic

Csikszentmihalyi (1990) put deep engagement in a narrow channel: the task sits just beyond current skill, hard enough to demand full attention, close enough to feel winnable. A single worksheet at a single difficulty cannot put a mixed class in that channel; it bores the top and panics the bottom. The fix is not thirty worksheets. It is one objective with graded entry points that students choose between, and permission to move up mid-task. (Manning's flow-state-condition-designer skill audits an activity against the full set of flow conditions.)

In practice

Here is a task for my [year group] [subject] class:
[paste task]
Objective: [learning objective]
Rewrite it as three versions of the SAME objective:
1. Mild: heavy scaffolding, worked entry, small steps.
2. Medium: some scaffolding, standard demand.
3. Spicy: minimal scaffolding, extends the idea.
Rules: all three must hit the same objective, spicy
must extend thinking rather than add volume, and each
version must state a concrete finish line the student
can check for themselves.

• Offer the same objective at three entry points, labelled by demand rather than ability: mild, medium and spicy works from Year 3 to Year 13.
• Make moving up the visible norm: finish two questions at your level and the rule is you step up one.
• Keep the goal concrete and the feedback immediate; ambiguous success criteria kill absorption faster than difficulty does.
• Watch for campers at the easy tier and nudge privately; choice of level is a scaffold, not a hiding place.