Fetch out jigsaw. Find narrow screwdriver. Release sliding plate and front guard. Insert blade, turn blade. Secure blade. Move plate into position, screw plate in place. Push guard into place firmly. Find extension lead. Feed from house to garden. Fetch workmate. Set up and adjust workmate. Take large board into garden. Secure large board between table and workmate. Measure in half the distance, mark and clearly set the line. Adjust jigsaw. Plug in jigsaw.
Spend the four seconds it takes to cut the half-inch board the four foot of its length.
Unplug jigsaw, complete all in reverse. Comfort oneself how much more arsey it would all be with a conventional saw.
Drink a glass of wine.