Math Mammoth Grade 7-B worktext (international version, 2025 edition) is the second part of a complete math curriculum for 7th grade. This is a pre-algebra course, and students can continue to algebra 1 after studying it. Part B starts out with a study of ratios and proportions (chapter 6). Students study unit rates, proportions, proportional relationships, scale drawings and floor plans. The next chapter provides thorough lessons on the concept of percent. Students learn to solve a wide variety of problems involving percentages, including percentage of change and simple interest problems. Geometry is our focus in chapter 8. Students draw geometric figures with given conditions (e.g. a triangle with 60° and 50° angles and a 6-cm side), and they also learn some basic geometric constructions. The other themes of this chapter are various angle relationships, area and the perimeter of a circle, conversions between units of area and of volume, surface area, volume and cross-sections when solids are sliced with a plane. Chapter 9 is an introduction to probability. Besides learning the basic idea behind probability as the ratio of favorable events to all possible events, students compare experimental probabilities to theoretical ones in probability simulations and even design some on their own. Lastly, in chapter 10, the curriculum covers statistical concepts. The major areas of study are random sampling and learning to compare two populations using some basic statistical measures and graphs. The worktext is customised for the international audiences in these aspects: * The curriculum uses the metric measurement units. Imperial units, such as inches and pounds, are not used. * Spelling conforms to British international standards (British English). * Page (paper) size is A4. * Large numbers are formatted with a space as the thousands separator (such as 12 394). (Decimals are formatted with a decimal point.) In money-related word problems, the book uses the dollar symbol $. The student worktext 7-A, an answer key book, and a book containing cumulative reviews and chapter tests are available for purchase separately on Lulu.