Math Mammoth Measuring 1 is a worktext that covers measurement-related topics over the span of three grade levels (grades 1-3; ages 6-9 years). Being a worktext, it contains both explanations of the concepts (the “text”) and exercises (the “work”). The lessons cover measuring length, weight and volume using the most common metric and customary units, and some easy conversions between the units. In general, the lessons require very little teacher preparation; however in several you will need to have on hand common measuring tools, such as a ruler, a scale or measuring cups. This book is not organized by grade levels. Instead, the lessons are grouped by topic. The first part of the book (up to the lesson Review 1) deals with measuring length, in increasing difficulty. The very first lessons deal with the concept of measuring length. Children use paperclips and other improvised units to measure the length of objects. The following lessons bring in whole inches and centimeters, and teach students how to measure the length of objects using a ruler and a measuring tape. Then there are lessons that also include feet, yards, miles, meters, and kilometers. Then follow four lessons about weight (mass). In these lessons, students use a bathroom scale and a kitchen scale to weigh objects both in metric and customary units. Then the book also has two lessons about volume (one for metric, one for customary units), which include many hands-on activities. When it comes to measuring, experience is the best teacher. We all use various measurement units in our everyday life, and using them is the key to remembering what they are and how to convert between them. The units your student is not using are likely to be forgotten easily. So encourage your student to have free “play time” with measuring devices such as scales, measuring cups, measuring tapes and rulers. Math Mammoth also has another worktext about measuring, Math Mammoth Measuring 2, which is a sequel to this one. In it, students practice measurement unit conversions and problem solving. The answer key is included (appended).