Students learn how to solve a mathematical equation with a missing addend. Students will learn the combinations of addends to find the sums of nine and ten. Students practice math facts with accuracy and immediacy for sums of nine and ten.

Review the combinations of addends to make the sum of nine or ten using manipulatives. Model if necessary. Children record the combinations in their math notebooks. Also, encourage them to look for the patterns and relationships of the addends. Then model taking the second addend out of the equation.

Using the TI-10 Overhead, demonstrate the game. Roll a dice. For example, a three is rolled. The game is continued for as long as you wish. Children should use manipulatives, if needed. You may scroll up on the screen using the arrow key to check accuracy and problem solve.

Review what the role of the calculator and the role of the operator are. What did they notice as they played Fast Nines or Fast Tens? What helped them with calculating the missing addend? Ask the children to think of other ways they could use this problem-solving tool.