Unit 8- Ten Frames and Teen Numbers

The focus of this unit is on understanding and solving addition and subtraction problems in a variety of contexts (i.e., games, activities, story problems), recording and representing solutions on paper, making sense of the teen numbers (10–19) as a group of ten ones and some number of leftovers, and counting by 1s and 10s to 100. Students solve story problems and discuss and compare their solution strategies with classmates. They practice counting by 10s as they count the number of fingers on 10 students. They play games where the cards that indicate how far to move (or how many to take) have “facts” on them, so that students develop fluency adding and subtracting within 5 (e.g., 3 + 2 and 4 - 1). They also work on a variety of activities that involve number combinations focusing specifically on combinations that make ten and on the teen numbers. 

Related Activities to Try at Home 

Counting While we continue to focus on strategies for counting a set of 20 objects accurately, we are also practicing the rote counting sequence with larger numbers. As a class, we often count aloud from one number to another. For example, we might start at 40 and count to 55. Find opportunities to count aloud together, letting your child pick the starting and ending numbers. In addition to counting by ones, we have begun to learn the counting by 10s sequence. You can also practice counting together by 10s to 100.

 Addition and Subtraction We’ve been solving addition and subtraction problems, and thinking about strategies for solving subtraction problems. Find ways to present problems about common situations: “Usually, we have five people at our dinner table, but Maria is eating at a friend’s house. How many people will there be?” Or, “There were six cookies, but Joe took two for snack. How many are left?” Encourage children to explain how they solve such problems. Most kindergarteners show the starting amount with counters or on their fingers, remove the amount that is taken away, and then count how many are left. Some may count back or “just know” some answers. 

Combinations of 10 Ten is an important number in our number system, so we’ve been thinking about how to make 10. For example, how many dots are there? How many more do you need to have 10? You can play a similar game with your fingers. Display a number of fingers, and ask, “How many to 10?” Students can represent and solve such problems on their fingers. 

Measuring Weight We’ve been comparing objects to see which is heavier. Find opportunities to ask your child about the weight of different objects. For example, “What do you think is heavier, the milk carton or the cereal box? Why do you think so?” Encourage your child to hold one item in each hand to feel which weighs more.