**Chapter 6- Model Two-Digit Subtraction**

**Summary**

**6-1 Subtract Tens:** I can use mental math and basic facts to subtract tens.

**6-2 Count Back Tens and Ones:** I can count back by tens and ones to subtract.

**6-3 Regroup Tens as Ones:** I can understand numbers with and without regrouping.

**6-4 PSS: Write a Number Sentence:** I can use *write a number sentence* as a strategy to solve problems.

**6-5 Subtract One-Digit Numbers from Two-Digit Numbers:** I can subtract one-digit numbers from two-digit numbers with and without regrouping.

**6-6 Subtract Two-Digit Number:** I can subtract two-digit numbers with and without regrouping.

**6-7 Check Subtraction:** I can check my subtraction by using addition.

**6-8 PSS: Choose a Strategy:** I can choose the best strategy to solve problems.

**6-9 Estimate Differences:** I can estimate differences by rounding to the nearest tens.