The purpose of this activity is for students to find products of a number of tenths and a number of tenths written as decimals. Students can think of finding these products in many ways including:

• Using a diagram.
• Using whole number arithmetic and place value reasoning or properties of operations (MP7).

• Invite students to share their reasoning for .
• Display a student generated diagram of or the diagram in the Student Responses.
• “¿Cómo se muestra  en el diagrama?” // “How does the diagram show ?” (There is 2 tenths of 4 tenths of the rectangle shaded.)
• “¿Cómo supieron que la región sombreada tiene un área de 0.08 unidades cuadradas?” // “How did you know that the shaded region has area 0.08 square units?” (There are shaded pieces and each one is of the full square.)
• Display equation .
• “¿Cómo se muestra esta ecuación en el diagrama?” // “How does the diagram show this equation?” (The shaded part is 2 tenths of 4 tenths of the rectangle so that's . It’s because there are pieces and each one has area or one hundredth of a square unit.)

• Using a diagram.
• Using whole number products and place value understanding.
• Using expressions to show their thinking.

• Invite students to share their responses and reasoning for the product .
• Display a student generated diagram or the diagram in student solution.
• “¿Cómo se muestra  en el diagrama?” // “How does the diagram show ?” (There is a full group of 0.4 and then there is 8 tenths of another group of 0.4.)
• “¿Cómo se muestra  en el diagrama?” // “How does the diagram show ?” (There is an 18 by 4 array of pieces and each piece is a hundredth of the whole.)
• Display:
• Invite students to share their responses about the products , and .
• “¿Cómo pueden usar un producto de números enteros para encontrar un producto de números decimales?” // “How can you use the whole number product to find decimal products?” (I just think about how many tenths or hundredths I have.)