post 8: What Makes a Teen Number?

Post 8: What makes a teen number?

Personal Objective: 

The personal objective for this blog is to help students understand the base-ten structure of teen numbers. Prior to this activity students should recognize that a full 10-frame represents 10 without having to count each dot (subitize), and also that a 10-frame can be partially filled to represent numbers less than 10. In order to complete the worksheet students should know the meaning of the equals and plus signs. The teachers focus is developing numeracy fluency and computational fluency. The students should have efficient, accurate, generalizable methods (algorithms) for computing numbers that are based on well-understood properties and number relationships (NCTM, 2000, p.144). 

Common Core Standard:

K.NBT.A.1

Compose and decompose numbers from 11 to 19 into ten ones and some further ones, e.g., by using objects or drawings, and record each composition or decomposition by a drawing or equation (e.g., 18 = 10 + 8); understand that these numbers are composed of ten ones and one, two, three, four, five, six, seven, eight, or nine ones.

Activity:

This activity can first be done orally, in a small teacher-led group or in pairs, using just the 10-frames and some counters. For struggling students who need more support and do not know teen number names can use a number line or number chart. 

You can watch this video: https://www.youtube.com/watch?v=3fTCAicmUWY.

What Makes a Teen Number?

Task: Decompose teen numbers using 10-frames and a number equation.

Materials:

Number cards 11-19

Pencil, crayon, or marker

Attached student worksheet

number line or number chart

This activity can be done individually, in partners, or in small groups. The students have a teacher-made sheet and a writing implement. The cards are shuffled and placed face down.

The student picks a card off of the top of the pile. The student then says the number and draws that many dots beginning with the first 10-frame. When the first 10-frame is filled, the student continues drawing the remaining dots in the next 10-frame. The student then fills in the blank equation with the corresponding numbers.

Example:

The student continues to pick cards and illustrate numbers in this way until all cards are used or the sheet is filled.

Attached Resources: student worksheet/blackline master 

Solution:
Here is the solution for number 13:

The solutions for 11-19 follow the same pattern.

Activity taken from: http://tasks.illustrativemathematics.org/content-standards/K/NBT/A/1/tasks/1404

Other Resources:

Reflection:

    Math was always a challenge for me therefore I would like to show my students many possible ways in which math doesn't become scary and my students begin to fear it. my students should develop a natural number sense so that they can be comfortable enough to solve computations flexibly and efficiently using their understanding of place value and relationships between numbers . This natural development of numbers will as stated in the source of this blog, "progress from the concrete to the abstract, from counting all (e.g. physically making four counters and then making twelve and counting all the counters to get sixteen) to counting on (e.g. counting four more starting at twelve to get to sixteen( to using part-whole (e.g. splitting apart the twelve to ten and two, and adding the two to four, then adding the ten) and relational thinking (knowing that 4 + 10 is 14 so 4 + 9 would be just one less)."