# 6.5 Arithmetic in Base Ten

### Lesson 1

• I can use decimals to make estimates and calculations about money.

### Lesson 2

• I can use diagrams to represent and reason about addition and subtraction of decimals.
• I can use place value to explain addition and subtraction of decimals.
• I can use vertical calculations to represent and reason about addition and subtraction of decimals.

### Lesson 3

• I can tell whether writing or removing a zero in a decimal will change its value.
• I know how to solve subtraction problems with decimals that require “unbundling” or “decomposing.”

### Lesson 4

• I can solve problems that involve addition and subtraction of decimals.

### Lesson 5

• I can use place value and fractions to reason about multiplication of decimals.

### Lesson 6

• I can use area diagrams to represent and reason about multiplication of decimals.
• I know and can explain more than one way to multiply decimals using fractions and place value.

### Lesson 7

• I can use area diagrams and partial products to represent and find products of decimals.

### Lesson 8

• I can describe and apply a method for multiplying decimals.
• I know how to use a product of whole numbers to find a product of decimals.

### Lesson 9

• I can use the partial quotients method to find a quotient of two whole numbers when the quotient is a whole number.

### Lesson 10

• I can use long division to find a quotient of two whole numbers when the quotient is a whole number.

### Lesson 11

• I can use long division to find the quotient of two whole numbers when the quotient is not a whole number.

### Lesson 12

• I can divide a decimal by a whole number.
• I can explain the division of a decimal by a whole number in terms of equal-sized groups.
• I know how multiplying both the dividend and the divisor by the same factor affects the quotient.

### Lesson 13

• I can explain how multiplying dividend and divisor by the same power of 10 can help me find a quotient of two decimals.
• I can find the quotient of two decimals.

### Lesson 14

• I can use addition, subtraction, multiplication, and division on decimals to solve problems.

### Lesson 15

• I can use the four operations on decimals to find surface areas and reason about real-world problems.