5th grade addition of 3 decimals numbers scientist game - Decimal numbers have a point at before or after some digits. The values of the numbers found after a decimal point significantly differ from those that come before. When adding decimal numbers, the same principles of addition apply however, adding numbers over decimal points follows specific rules which students need to master. If for example two numbers to the right of a decimal point are added and the outcome is more than or up to 10, the value will be rounded up to 1 and sent over the decimal point to add to the nearest value. Students need to understand how to add decimal numbers by studying the rules that apply to such addition facts. This is an interactive online math game for students in 3rd, 4th , 5th and 6th grades.