<script> let count = 1; // the `$:` means 're-run whenever these values change' $: doubled = count * 2; $: quadrupled = doubled * 2; function handleClick() { count += 1; } </script> <button on:click={handleClick}> Count: {count} </button> <p>{count} * 2 = {doubled}</p> <p>{doubled} * 2 = {quadrupled}</p>