A close-up view of a calculator or electronic device with a black background. White alphanumeric symbols and numbers are visible, indicating various mathematical or scientific units.
A beige calculator with multiple buttons, featuring a display that shows the number 3.14. The calculator has a solar panel and various function keys, including numerical digits, mathematical operations, and memory functions.
A close-up view of an open book with text written in English. The focus is on the middle to bottom part of the page, displaying a passage with numbers related to weight measurements. The page is slightly curved, indicating the book is partially open.