Book excerpt: Measuring, Grade 4 Workbook includes lessons on temperature, length, weight, and volume. The focus is on conversions between the units and on word problems that involve conversions. Students may have difficulty with the conversions, and that is why they should also be studied in 5th grade. At this point, students should be able to easily convert from a bigger unit to a smaller unit (such as converting 3 feet into 36 inches, or 2 kg into 2,000 grams). While the Common Core standards do not include them for 4th grade, I have also included some problems where we convert from a smaller unit to a bigger unit (such as 4,500 ml into 4 L 500 ml or 12 feet into 4 yards), because I feel most children are capable of doing these in 4th grade. If you feel your child has difficulty with these types of conversions (from a smaller unit to a bigger unit), feel free to omit those particular exercises. They are intermixed though, and not marked in any special way. There are separate lessons for customary units and for metric units. These lessons include a chart that lists the units and the conversion factors. For metric units, those charts always include all the units, even when they are not in common usage. For example, one lesson only deals with milliliters and liters. However, the chart in that lesson also shows the two other units (deciliters and centiliters) in order to help familiarize the students with these two basic ideas of the metric system: The units always differ by a factor of ten; The units are named consistently with the same prefixes (milli-, centi-, deci-, deka-, hecto-, and kilo-). These prefixes and their meanings are not yet studied in detail in fourth grade. You may, of course, at your discretion, explain them to the student.