They incorporate concepts of linear measurement, weight measurement, area, force and motion, properties of shapes, simple machines, and scientific process. (tes.com)
In the Japanese textbook series we often use in Lesson Study work, fractions are introduced in the context of linear measurement, as fractions of a meter. (lsalliance.org)
Grade One students will learn linear measurement with non-standard units (ex: hand spans) and standard units (ex: inches or centimeters), as well as temperature using a thermometer, time using calendars, etc.. (gigglelearn.com)