Friendly Numbers Addition strategy By Lindsay Esterline Friendly Numbers We like being with our friends! Our friends are easy to work with! Well, some numbers are easier to work with when we add. Some numbers are more friendly than others! 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 The “tens” are your friendly numbers! Making a Ten Now that you know that the tens are your friendly numbers, it will be important that you know how to make a ten. It’s easy! You just need to remember your fact rainbow! How do you use friendly numbers to add? 1. Make a ten 21 + 16 = -1 20 + 16 = 36 + 1 = 37 2. Write your new number sentence 3. Reverse your first step TIP: If you get stuck adding your new number sentence, use what you know about place value (expanded form)! 16 = 10 + 6, so your new sentence could be 20 + 10 + 6 = 36! How do you use friendly numbers to add? 37 + 28 = +2 37 + 30 = 67 - 2 = 65 2. Write your new number sentence 1. Make a ten 3. Reverse your first step Now, you try it! 46 + 23 = -3 46 + 20 = 66 + 3 = 69 2. Did you write your new number sentence? 1. Did you make a ten? (Was it the easiest number to reverse?) 3. Did you reverse your first step? HINT: Think about your fact rainbow for making a 10! What number could you add/subtract to make a friendly number, AND would be the easiest to reverse at the end? Now, you try it! 1. Did you make a ten? (Was it the easiest number to reverse?) 47 + 35 = +3 50 + 35 = 85 - 3 = 82 2. Did you write your new number sentence? 3. Did you reverse your first step? Now, all on you own! 1. Did you make a ten? (Was it the easiest number to reverse?) 58 + 26 = +2 60 + 26 = 86 - 2 = 84 2. Did you write your new number sentence? 3. Did you reverse your first step? HINT: Think about your fact rainbow for making a 10! What number could you add/subtract to make a friendly number, AND would be the easiest to reverse at the end? Review Do you always have to subtract to make a friendly number? No, you can add to make a friendly number! Do you always have to make the first number friendly? No, you can make either number in the sentence friendly! Do you always have to reverse your first step? YES, or your answer will be wrong! Name ___________________________ Date _________________ Solve each addition problem using the friendly numbers strategy. 1. 2. 3. 4. 5. 6. 7. 8. Mrs. Esterline’s Establishment Thank you for downloading my product! Please provide feedback—it not only helps to improve the quality of my products, but ensures the success of my store! My goal is a 4.0 rating and happy customers! Follower Benefits include off new products for the first 48 hours of its release! By following me you will be notified of all of my new products! I’m just getting started! So check back often for new products! Terms of Use Copy right © Mrs. Esterline’s Establishment (Lindsay Esterline). All rights reserved by author. This product is to be used by the original downloader only. Copying for more than one teacher, classroom, department, school, or school system is prohibited. This product may not be distributed or displayed digitally for public view. Failure to comply is a copyright infringement and a violation of the Digital Millennium Copy right Act (DMCA). Clipart and elements found in this PDF are copyrighted and cannot be extracted and used outside of this file without permission or license. Intended for classroom and personal use by the original downloader ONLY. This resource may not be uploaded to any website for download. I do, however, appreciate and encourage linking back to my store for others to purchase and download products directly from my TpT store.