Lesson 26: Number Bonds
Lesson Objectives
- Represent and use number bonds within 20
- Apply TouchPoints on lesser numerals
- Identify pairs of numbers whose sum or difference is within 20
- Use TouchPoints as a strategy in computation
- Join or take away groups of objects to add or subtract
- Add or subtract using Pictorial TouchPoints
- Count on or backwards using TouchPoints
Materials
- Extend Workbook (Page 26)
- Counters or manipulatives
- TouchMath’s Foam Numerals with TouchMath’s TouchPoints with or without pictures
- Number bond template
- Highlighters, markers, or crayons
- TouchMath’s number line
Step 1: Warm Up (5 min)
Explain to your students that number bonds are like a pair of numbers that are added together to make a larger number. They can also be used to break down a larger number (with subtraction). Show some visual examples. Start with the number 5 and ask what two numbers add up to make 5? Place 5 in the top circle of the number bond and put 1 and 4 in the other two circles. You can also draw dots instead of placing the numbers 1 and 4 in the circles to help represent those quantities. To another number bond for 5 with addends of 2 and 3.
Step 2: Vocab Review (5 min)
Introduce number bonds today, which is just a visual representation between the parts (numbers) and the whole (the sum). It can also be used to find the difference between two numbers. They help us to visualize the connection between numbers. They help use to quickly solve addition and subtraction problems and help us to see how numbers can be part of a whole.
Step 3: Model (5 min)
Now show number bonds of 10, and this time color the sum (top circle) one color (e.g. blue) and the bottom circles another color (e.g. yellow). Then, re-write all the number bonds for 10 (1 and 9, 2 and 8, 3 and 7, 4 and 6, and 5 and 5). Following this, write all the addition sentences below it: 1+9=10, 2+8=10, and so forth. The addends should be yellow and the sums blue. Now, introduce subtraction number bonds using 5 (e.g. 5-1=4, 5–4=1, and so forth). Again, the difference should be one color (same as the sums, blue), while the other two numbers should be another color (just like in our addition problems, yellow). You can also explain that the yellow numbers are parts and the blue numbers are whole, helping to expand on whole-part relationships.
Step 4: Guided Practice (5 min)
When having students first practice number bonds on their own or with guided support, use manipulatives to represent the numbers, whether the TouchPoints, counters, or other actual items (e.g. food, candies, toys, blocks, etc). Arrange the objects into parts and wholes to get the students to answer number bond questions relating to the objects (e.g. 5 candies in the top circle, and 2 and 3 candies in the bottom circles; 5-3=2; or 2+3=5). Give students different addition or subtraction problems and let them represent those problems using the selected objects of your choosing in the number bond templates.
Step 5: Student Practice (5 min)
Go to Student Workbook Page (26). Read the directions at the top of the page. Tell students they will answer the addition and subtraction problems using number bonds. Looking at the first problem, have students find the larger number in the addition problem (9), using their TouchMath number line. Have students follow the correct computation order: 1) Say the larger number and cross it off, 2) count on the TouchPoints of the other number (10,11,12,13), then write the answer on the line provided to the right of the equation sign (13). Following this, students should repeat the math fact: 4+9=13. Place the 13 in the top circle of the number bond and explain this number bond represents 4+9. Work through the next 5 problems, paying attention to the computation sign (+/-), and remembering to cross off the larger number and to either count on or backwards on the next number to find their answer. Remind them to put their answer on the line provided but also in the circle within the number bond.
Step 6: Wrap Up (5 min)
To wrap up the lesson, review the learning objectives and core vocabulary words again and ask your students about their experience.
