Have students start a small cut in the wood. Then measure the cut. That’s the kerf. Now that they have the 16ths on the board, they should be able to accurately measure the gap.
So, we now have the gap. They should now be able to measure the piece of wood and deduct the gap. Once the gap measurement is subtracted, they could be asked to cut the wood in two.
Questions: how long is each piece of wood?
How long would one of them have been if we didn’t have a kerf to deal with?
More exercises with tape measures and a saw…
Cut a piece of wood in half and end up with two pieces exactly the same length. (remember the kerf.)
Ask them to cut a piece to an exact length.
Ask them to cut at a 45degree angle.