Abstract: A device for testing body fluids is disclosed, the device comprising an electrode body having an enclosed flow chamber extending longitudinally therethrough. A valve assembly is in liquid communication with the flow chamber and also detachably mounts a syringe thereon. The valve assembly provides liquid communication between a syringe mounted thereon and the flow chamber. A plurality of electrode cells is detachably mounted to the electrode body and is in liquid communication with the flow chamber. The plurality of electrode cells measures electrical resistivity, rH.sub.2, and pH. A circuit electrically connects the plurality of electrodes to an interface providing data output and command input.

Abstract: An electronic teaching device (10) provides several mathematical activities including Place Value, Trade, Target, Solve It, Word Problems, Estimate, Select and Calculator. The Place Value activity enhances the understanding of numbers by pictorially displaying the place values. The Trade activity enhances the understanding of addition and subtraction by allowing the user to trade between the ones' place value and the tens' place value to properly perform a mathematical operation. The Target activity emphasizes logical reasoning and problem solving. The Solve It activity uses the place-value system to develop logical reasoning.The Word Problems activity tests the user's knowledge of basic mathematical terms and facts. The Estimate activity develops the ability to estimate answers to problems. The Select activity allows the user to recognize basic math operations.

Abstract: An electronic teaching device (10) provides several mathematical activities including Place Value, Trade, Target, Solve It, Word Problems, Estimate, Select and Calculator. The Place Value activity enhances the understanding of numbers by pictorially displaying the place values. The Trade activity enhances the understanding of addition and subtraction by allowing the user to trade between the ones' place value and the tens' place value to properly perform a mathematical operation. The Target activity emphasizes logical reasoning and problem solving. The Solve It activity uses the place-value system to develop logical reasoning.The Word Problems activity tests the user's knowledge of basic mathematical terms and facts. The Estimate activity develops the ability to estimate answers to problems. The Select activity allows the user to recognize basic math operations.

Abstract: An electronic teaching device (10) provides several mathematical activities including Place Value, Trade, Target, Solve It, Word Problems, Estimate, Select and Calculator. The Place Value activity enhances the understanding of numbers by pictorially displaying the place values. The Trade activity enhances the understanding of addition and subtraction by allowing the user to trade between the ones' place value and the tens' place value to properly perform a mathematical operation. The Target activity emphasizes logical reasoning and problem solving. The Solve It activity uses the place-value system to develop logical reasoning.The Word Problems activity tests the user's knowledge of basic mathematical terms and facts. The Estimate activity develops the ability to estimate answers to problems. The Select activity allows the user to recognize basic math operations.