EL Support Lesson
Three Part Trains
Students will be able to add three whole numbers whose sums are within 20.
Students will be able to explain the steps to add three whole numbers using manipulatives and peer support.
- Display a bag, and tell students that there are ten cubes in the bag.
- Show students three different color cubes: red, blue and yellow. Label each color cube.
- Ask students, "How many of each color could there be in the bag?"
- Display the sentence frame, "There could be ____ ____ cubes, __ _____ cubes, and ____ ____ cubes." Remind students that in English the adjective comes before the noun that it describes (e.g. the red cube, not the cube red).
- Model a possible solution, "There could be four red cubes, three blue cubes, and three yellow cubes." Draw the cube combination on the board. Remind students that "could" means that there may or may not be that many.
- Model other possible combinations. Ask guiding questions such as, "If there are three red cubes and three blue cubes, how many yellow cubes would there be?" Think aloud, adding three and three, and then subtracting six from the total number of cubes, ten.
- Dump the cubes from the bag so that students can see them, and write an equation that shows the number of cubes of each color on the board.
Explicit Instruction/Teacher modeling(10 minutes)
- Tell students that today they will build trains with linking cubes of three different colors.
- Explain that the trains must be exactly ten cubes long.
- Project the Three Part Cubes Train worksheet, and model building a train with linking cubes. Think aloud, "I want to start with six blue cubes, and add one red cube. How many total cubes do I have so far? (Seven.) How many more cubes do I need to have a total of ten? (Three.) Yes, I will add three green cubes for a total of ten."
- Next, color a train on the worksheet to match the linking cube train. Model counting the squares as you color to exactly match the cubes.
- Write an equation that shows how many of each color cube was used to build the train.
- Remind students that since you are combining different parts together you will use addition. Tell students that the parts of the train are addends in the number sentence, or numbers that are added to other numbers. The different colored cubes are parts of the whole train.
- Ask student which math symbol is used to show addition. (Plus sign.) Point to the plus sign on the worksheet, and remind students that you will count on to find the total number of cubes.
- Ask students which math symbol shows that the amounts on either side of it are the same. (Equal sign.) Show students the equal sign on the worksheet and think aloud, "Yes, when I add the parts of the train that number of cubes is the same as the total number of cubes all together."
- Review that the sum, or total number of cubes for all trains, is ten. Show students where to write the sum on the worksheet.
Guided Practice(10 minutes)
- Distribute one Three Part Train worksheet to each student.
- Review the steps for the activity:
- Use three different colors to build a train that is ten cubes long
- Color cubes on the worksheet to match the train
- Write an equation to show how many cubes are in each part of the train
- Tell students to turn and talk to a partner and review the steps to do the activity in their own words.
- Distribute an assortment of linking cubes and crayons to small groups of students, and tell students to begin. Students should try to create and color four different trains. If students finish early, challenge them to create other combinations of ten, and write more equations on the back of the worksheet.
- As students work, circulate and check that they are able to build three part trains using ten cubes. Check that the picture and equation match the train. Ask guiding questions such as, "How many yellow cubes did you use?" and "How many more cubes will you need to build a train that is ten cubes long?"
- Instruct students to point to the parts of the train as they read their equations aloud.
Group work time(10 minutes)
- After students have finished building four trains, tell them that they will describe a train from their worksheet to a partner.
- Partner A will say, "The train has ____ ____ cubes, ____ ____ cubes, and ____ ____cubes." Display the sentence frame for reference.
- Partner B will build the train, and then say an equation, "____ + ____ + ____ = 10."
- Partner A will check whether the train matches the drawing, and give a thumbs up if Partner B built the train correctly.
- Partners will switch roles. Partner B will describe a train, and Partner A will build the train and name the parts with a number sentence.
Additional EL adaptations
- Display the number names from 1-10 and color names for reference.
- Work in a teacher-led small group to build cube trains and write equations.
- Challenge students to decribe their train to a partner without using the sentence frame.
- Instruct students to explain the steps to add three parts to find a whole in their own words.
- As students work, check that they are able to count accurately to build equations with three parts that equal ten.
- Check that students are able to show more than one combination of numbers that equal ten.
- Observe that students are able to accurately describe their train to a partner, placing the adjective before the noun to describe the different color linking cubes.
- Assess listening comprehension as students follow a partner's instructions to build a train.
Review and closing(5 minutes)
- Close with a story problem, "Asha loves fruit. Her mom slices up a pear, an apple and an orange. She tells Asha that she can have ten slices of fruit total. Use your cubes to show possible combinations of fruit that Asha could choose."
- Tell students to use green cubes to show pear slices, red cubes to show apple slices and orange cubes to show orange slices. Challenge them to show more than one combination.
- Choose studentst to share possible combinations. For example, Asha could choose two pear slices, four apple slices, and four orange slices because 2 + 4 + 4 = 10.
- Ask students how the cubes help them solve the problem. Provide the sentence frame, "The cubes helped me because ____."