Activating Strategy

• What mathematical relationships do you notice?

• What do you notice about the units used in the problem?

• How do the units given for the amount a shelf can hold compare to those given for the mass of items on the shelf?

There seem to be multiple steps in this problem, so let’s read it carefully and summarize what we know and what we are trying to figure out. I notice that there are two different units of measure. First, let me think about the information the problem has given me that might help me solve the question asked. I know the shelf can hold 5,000 grams. I also know that the picture frame and the plants have a total mass of 3 kilograms plus 245 grams.  I also know Chuck wants to be able to add two more plants to the shelf.  I am solving for the greatest possible mass of two vases that Chuck can add to the shelf if the shelf holds a maximum of 5,000 grams.

I notice that there are two different metric units for mass in this problem: grams and kilograms. Since 1 kilogram is 1,000 grams, I can use this information to help me figure out how many grams are equivalent to 3 kilograms and 245 grams.

Let’s start by determining the combined mass of the picture frame and plants.

If 1 kilogram (kg) equals 1,000 grams (g), 3 kilograms would be 3 x 1,000 grams or 3,000 grams. Then I would need to combine the 3,000 grams and the 245 grams. 

The combined mass of the picture frame and plant is 3,245 grams.

Now that we know that the combined mass of the picture frame and plant is 3,245 grams and the maximum mass the shelf can hold is 5,000 grams, we can solve for the greatest possible mass of the two picture frames Chuck wants to add to the shelf. We can represent this with a bar model.

From the bar model, I can see that I can subtract 3,245 from 5,000 to solve for x or add up from 3,245 to find the difference. I can represent this with two equations.

Watch as I write the following equations next to the bar model drawing:

Guided Practice

Now, mathematicians, it’s your turn:

When you are solving metric measurement problems that have more than one unit of measure, you will first need to make the units the same using measurement equivalencies. Also, when solving multi-step problems, it helps to think through the information you know, what you need to figure out, and the steps to the problems.

Independent Task

1. FRECKLE - Complete THREE Freckle Assignments each week. DUE FRIDAY. Your HIGHEST score in Targeted Practice is your weekly math grade - Click HERE for Freckle website

• GRADED Targeted Practice - Current skill (5 questions; Score Goal=80% or higher)

• Fact Practice - Multiplication Fact Practice

• Adaptive Practice - At YOUR level

2. iREADY Math - Complete 30 minutes at your level each week