https://www.khanacademy.org/math/cc-third-grade-math/imp-geometry/imp-count-unit-squares-to-find-area/v/measuring-the-same-rectangle-with-different-unit-squares 2021-06-30T20:49:37Z Measuring rectangles with different unit squares Sal finds area of a rectangle with different sized units. Sal Khan video https://cdn.kastatic.org/googleusercontent/XLyGX9NQrUw7zkofePUoYVl9aFQNSW3N6kBZEHokwrJ1F6se03K6EBxnfshCxChHYC5Ni9PKXpkwbHY127sNiouC Measuring rectangles with different unit squares Sal finds area of a rectangle with different sized units. https://cdn.kastatic.org/ka-youtube-converted/iNZZIb_-PA8.mp4/iNZZIb_-PA8.mp4 184 Area of rectangles https://www.khanacademy.org/math/cc-third-grade-math/imp-geometry/imp-area-formula-intuition/v/transitioning-from-counting-to-multiplying-to-find-area-3rd-grade-khan-academy 2021-07-07T20:19:25Z Transitioning from unit squares to area formula Lindsay finds the area of a rectangle both by counting unit squares and multiplying side lengths.  Lindsay Spears video https://cdn.kastatic.org/googleusercontent/0TcMAODNL5pHqeAqhsBwYzmo6XYyHkphibtUWYy4rg3HTA4BYrsKdKuo5yQlLqLYsBbb_UyhIGiQJ8mAh5GudWhX Transitioning from unit squares to area formula Lindsay finds the area of a rectangle both by counting unit squares and multiplying side lengths.  https://cdn.kastatic.org/ka-youtube-converted/mu3HHCdYYtY.mp4/mu3HHCdYYtY.mp4 202 Area of rectangles https://www.khanacademy.org/math/cc-third-grade-math/imp-geometry/imp-area-formula-intuition/e/finding-area-by-multiplying 2021-06-30T20:49:36Z Transition from unit squares to area formula Find area of rectangles by multiplying side-lengths. Lindsay Spears exercise https://www.khanacademy.org/math/cc-third-grade-math/imp-geometry/imp-multiply-to-find-area/v/finding-missing-side-when-given-area-math-3rd-grade-khan-academy 2021-07-07T20:19:25Z Finding missing side when given area Lindsay finds the missing side length on a rectangle when given the area of the rectangle.  Lindsay Spears video https://cdn.kastatic.org/googleusercontent/4UWiKYtz-XuI6D4Frqz2ieJ0yLETguWV59xwm8xc3ts4PeHKRNflaTcs04S-sjB0PXwfpIvkcj0Dhhz00vaLkPA Finding missing side when given area Lindsay finds the missing side length on a rectangle when given the area of the rectangle.  https://cdn.kastatic.org/ka-youtube-converted/_JdgDBzQ0Us.mp4/_JdgDBzQ0Us.mp4 184 Area of rectangles https://www.khanacademy.org/math/cc-third-grade-math/3rd-perimeter/perimeter-of-polygons-with-missing-side-lengths/e/find-a-missing-side-length-when-given-perimeter 2025-06-24T14:43:14.98588327Z Find a missing side length when given perimeter Find a missing side length for a figure when given the perimeter. Lindsay exercise https://www.khanacademy.org/math/cc-third-grade-math/imp-geometry/imp-area-formula-intuition/v/rectangle-area-as-product-of-dimensions-same-as-counting-unit-squares 2021-07-07T20:19:26Z Counting unit squares to find area formula Sal uses unit squares to see why multiplying side-lengths can also find the area of rectangles.    Sal Khan video https://cdn.kastatic.org/googleusercontent/stlR2hLpfqUfhlaLA1rKy8H9zxDvxEGD6edqlv1x1mvDZt_TDdE-iide8P6i7NGR_cnNQdkRDwsjUpENXZzeGTc Counting unit squares to find area formula Sal uses unit squares to see why multiplying side-lengths can also find the area of rectangles.    https://cdn.kastatic.org/ka-youtube-converted/DRg2VCo8lP0.mp4/DRg2VCo8lP0.mp4 320 Area of rectangles https://www.khanacademy.org/math/cc-third-grade-math/imp-geometry/imp-multiply-to-find-area/a/area-rectangles-review 2021-06-30T20:49:37Z Area of rectangles review Review the basics of area of rectangles and try some practice problems. article