# Lesson 11 Make Sense of Decimal Addition

## Warm-up How Many Do You See: Grids

How many do you see? How do you see them?

## Activity 1 The Sum

1. Find the value of the expression. Show your thinking. Organize it so it can be followed by others.

## Activity 2 Target Numbers: Add Tenths or Hundredths

Directions:

1. Play one round of Target Numbers.

• Partner A

• Start at 0. Roll the number cube. Choose whether to add that number of tenths or hundredths to your starting number.

• Write an equation to represent the sum.

• Take turns until you’ve played 6 rounds.

• Each round, the sum from the previous equations becomes the starting number in the new equation.

• The partner to get a sum closest to 1 without going over wins.

2. Describe a move that you could have made differently to change the outcome of the game.

## Problem 1

Mai and Tyler were playing “Target Number Addition.”

1. Mai rolled 6 sixes. How close can Mai get to 1 without going over?

2. Tyler rolled 6 fours. How close can Tyler get to 1 without going over?