Determine how much longer one object is than another and express the difference in terms of a standard unit by subtracting

Big Ideas: The difference between two measures of the same unit can be found by looking at their distance apart on a ruler/number line or by subtracting. This lesson builds on students' work with measuring with standard units and solving addition and subtraction problems by using a number line. This task asks students to measure a gummy worm. Students will compare and find the difference between the original size and it's size after being stretched. The goal is for them to describe the difference in words and numbers using a number line. The mathematical concepts in this lesson build toward students' future work with using addition and subtraction within 100 and representing whole numbers as lengths from 0 on a number line. Vocabulary: inch, foot, yard, centimeter, meter, ruler, yardstick, meter stick, measuring tape, estimate, length, equation, number line, equally spaced, addition, subtraction, unknown, sums, differences, measure, standard units, customary, metric, units Special Materials: Gummy Worms Number Line Ruler Yardstick Meter Stick Measuring tape cm cubes color tiles - 1 inch