For activities with important visual aids. Unit: 6.5 Arithmetic in Base Ten (Grade 6). 6.5 Arithmetic in Base Ten In this unit, students compute sums, differences, products, and quotients of multi-digit whole numbers and decimals, using efficient algorithms. They use calculations with whole numbers and decimals to solve problems set in real-world contexts. Read More Lessons Resources Assessments Lessons Warming Up to Decimals 1 Using Decimals in a Shopping Context Adding and Subtracting Decimals 2 Using Diagrams to Represent Addition and Subtraction 3 Adding and Subtracting Decimals with Few Non-Zero Digits 4 Adding and Subtracting Decimals with Many Non-Zero Digits Multiplying