A reference book for learning the basic concepts of mathematics. - Title: Focus Gold Mathematics III 4th Edition - Contents: Basic mathematical concepts and problem solving - ISBN: 978-4-8042-2831-7 It has been used a little, so there are some bent corners and writing. Please be aware of this if you are sensitive to such things! Thank you for looking. If you would like to purchase it together with the answer key, please let me know.