My kid is in the 4th standard and his Art is too bad. He is good in all other subject but in creativity and arts he always secures lower grades, Can you guys please advice me what shall I do to improv

My kid is in the 4th standard and his Art is too bad. He is good in all other subject but in creativity and arts he always secures lower grades, Can you guys please advice me what shall I do to improve his art? I've recently purchased drawing books, color paint, sketchbook from https://www.reecoupons.com/categories/back-to-school. He is doing practice yet but still I am too much tense for his Art. Need advice thanks.