SS3.2: Demonstrate understanding of measuring mass in g and kg

Measure It: Length, Time and Mass in the Real World Grade 3

Whose foot is the right ruler? How long is a minute, really? Is a kilogram of feathers lighter than a kilogram of rocks? Four lessons where students measure length, time and mass with real tools, then use their own data to settle an argument.

• Whose foot is the right ruler? 50–60 min

  Teams measure the same taped line on the floor in heel-to-toe steps and get different answers, then measure it again with metre sticks and all agree. Students explain why the world needs standard units, and measure their own feet to build a class line plot.

• How long is a minute, really? 50–60 min

  With eyes closed, students raise a hand when they think one minute has passed while a partner times them to the second. The class builds a line plot of its guesses, tries again with a counting strategy, then solves elapsed-time problems taken from its own school day.

• Which weighs more, a kilogram of feathers or a kilogram of rocks? 55–60 min

  Teams build a coat-hanger balance to compare classroom objects, estimate masses in grams and check them on a kitchen scale, then heft three bags that look very different but may or may not have the same mass. Students explain why size doesn't tell you mass.

• Can we design the best paper airplane? 55–60 min

  Teams fold a classic dart and their own design, fly each one five times from the same line, and measure every flight with a tape measure. Students find the middle value for each design, plot the class results, and use the data to argue which design really flies farther.