Thank you for reading my "Transformation Tuesday" series. Today's post marks the last "Transformation Tuesday" post until September. Until that time, I will be featuring a Summer PD series from June through July. Be sure to check back each week for some new summer learning, in between relaxing at the pool and vacationing of course! :o)

Today's post features my favorite critical thinking web games. They are sure to keep your students engaged in these last few days. There are two Coolmath.com games that I would like to share with you-- Bridge Crossing and Water Jars. Both games require students to use their strategic thinking skills to successfully complete the activities. They originally appeared in my 2014 "Problem Solving Palooza" series. Check it out here.

The first challenge is one of my favorite web games. It's called "Bridge Crossing." See the screenshot and game details below.

**Grade Level:**This website is more suited to the reasoning skills of upper elementary/ middle school students. (See variations below for lower elementary challenges.)

**Objective:**Help all of the characters cross the bridge.

**Task:**Only two characters can cross the bridge at the same time. The lantern must be used when the characters cross the bridge. Each character shows how many minutes it takes him/her to cross the bridge. The lantern will lasts for 30 minutes; that's how long the characters have to cross the bridge because they cannot cross the bridge in the dark.

**Note:**This is a challenging task, but it is possible. I've had students master this task in the past!

**Ways to Utilize the Activity:**This website is a great way to get your student thinking about how to solve problems such as these. Consider displaying the website to the class and review the directions. Then, as a class, discuss ways to approach the task. Ask questions such as:

- What is the task asking us to do?
- What special conditions do we need to consider?
- Which characters take the shortest time to cross the bridge?
- Which characters take the longest time to cross the bridge?
- How can we pair the characters together so that we use the shortest time possible?
- Which character can be easily used to travel back and forth across the bridge and hold the lantern?

This applet makes a great fast finisher activity. It can also be included on a math menu or used on a menu of problem solving station options.

**Variations:**The two websites below are more suited for younger elementary students. They are similar to the challenge above but include special conditions, such as a small penguin cannot be left alone on a side with an unrelated adult penguin. The special conditions add an additional element of challenge, but these tasks are easier than the "Bridge Crossing" task.

The second challenge is another one of my favorite web games. It's called "Water Jars." See the screenshot and game details below.

**Grade Level:**This website is more suited to the reasoning skills of upper elementary/ middle school students.

**Objective:**Measure 6 liters of water from a 5-liter jug and a 7-liter jug

**Task:**Fill-up the jars and use them to measure 6 liters of water. The jugs can be emptied, refilled, and transferred to the other container multiple times until the goal is achieved.

For example, if you fill up the 5-liter jug and then pour it into the 7-liter jug, you can refill the 5-liter jug and pour it into the 7-liter jug leaving 3 liters in the 5-liter jug. You've just measured 3 liters.

Students will need to make moves like the one above to measure 6 liters.

**Note:**This is a challenging task, but it is possible. I've had students master this task in the past!

**Ways to Utilize the Activity:**This website is a great way to get your student thinking about how to solve problems such as these. Consider displaying the website to the class and review the directions. Then, as a class, discuss ways to approach the task. Ask questions such as:

- What is the task asking us to do?
- What special conditions do we need to consider?
- How can we measure different amounts, other than 5 liters or 7 liters, using these two jugs? Let's try to measure 3 liters.
- What's the purpose of being able to fill the jug and transfer it to the other jug?

This applet makes a great fast finisher activity. It can also be included on a math menu or used on a menu of problem solving station options.

**Variations:**This activity can be simulated in the classroom with actual jugs of water. Set the situation up by saying that you need to measure ____ liters of water but you only have a ____-liter jug and a ____-liter jug. Try using this model to support the students' understanding of the task before using the website for struggling or younger students.

**Sound Off!**What websites do you like to use to challenge your students' critical thinking?