# Surf for More Math

## CHAPTER 8: ADDITION AND SUBTRACTION

**Lesson 9: Solving Missing-Part Problems **

Use these interactive activities to encourage students to have fun on the Web while learning about adding and subtracting two-digit numbers. Students can try these activities on their own or in pairs.

**Goal**

Solve problems that involve a missing addend, subtrahend, or minuend.

[CN, PS, R, V]

**Instructions for Use**

**Addition Equations** gives students practice solving problems that involve a missing number in an addition equation.

To use Addition Equation, scroll down to the Practice section and click Start. Enter the missing number in the addition equation and click Check. A total of the number of correct and incorrect responses is shown. Click Report Totals to get a summary.

Scroll down to the Play section and select Countdown, Give Me Time, or 20 Questions. Click Start to begin answering the questions as in the Practice.

**Subtraction Equations** gives students practice solving problems that involve a missing number in a subtraction equation.

To use Subtraction Equation, scroll down to the Practice section and click Start. Enter the missing number in the subtraction equation and click Check. A total of the number of correct and incorrect responses is shown. Click Report Totals to get a summary.

Scroll down to the Play section and select Countdown, Give Me Time, or 20 Questions. Click Start to begin answering the questions as in the Practice.