In this lesson, children use concrete and pictorial models to represent tens and ones. Children see that 1 ten can be shown by filling a ten frame with 10 connecting cubes. Any extra cubes outside the ten frame are ones. Representing two-digit numbers in this way supports children’s understanding of the base-ten number system. When children make connections between models for teen numbers and an expression that gives the value in each place, these multiple representations will extend children’s understanding of place value and help establish a foundation for two-digit addition strategies.
To get students thinking about groups of 10, have two children stand in front of the class and hold up their hands with fingers spread. Ask the class:
Repeat the activity with groups of 3 to 9 children. Ask classmates to count by tens to find the total number of spread fingers.
I start by displaying the first slide of the PowerPoint, then I read the following problem aloud and have children model the problem with connecting cubes:
Tim has 10 pennies. He gets 2 more pennies. How many pennies does Tim have now?
Guide children to place the appropriate number of cubes inside the ten frames and then draw the cubes to represent their model.
Work through the model on the next PowerPoint slide with the children. Explain that the filled ten frame shows 10 ones, which is the same as 1 ten.
I then hand out the worksheet to the students, and review the model at the top of the page. Encourage children to model each problem as they complete the exercises.
Once students have grasped the concept, of ten and ones, I release them to complete the Worksheet on their own.
To close out the lesson, I have students show the number 12 using words, pictures, and tens and ones.