This randomised controlled trial experimental study compared the effectiveness of using two different types of visualisation -- "self-constructed visualisation" (SCV) and "passively received visualisation" (PRV) -- to help children with attention-deficit/hyperactivity disorder (ADHD) solve mathematical word problems. While SCV refers to drawings that children create to help solve given word problems, PRV refers to pre-made images that accompany word problems. Twenty children with ADHD in Kuwait, aged nine to 11 years, were randomly assigned to either the SCV or PRV group, where they were taught to use either SCV or PRV to solve word problems across 20 daily one-to-one sessions. The results showed that regardless of the visualisation type, children's word problem-solving ability significantly improved. Children with ADHD should thus be encouraged to use visualisation to help make the word problem-solving process more accessible to them.