Choose the addition strategy you wish to practise. You can use this resource to teach these strategies. Use the pen to model these strategies with the students. Each time you will get a different set of questions custom designed for each specific strategy. Just click the back button and select your activity again to change the questions. You can click the eye button to reveal/hide the answers. You can print each activity on two pages. Make it double-sided to save paper! You can also print the answer sheets. Allow the students who finish early to mark themselves and others using the answer sheets.

Doubles or Near Doubles: Students benefit from knowing the double facts such as 7+7=14 or 9+9=18. If you know these facts you can add near doubles such as 7+8 by finding double of 7 and adding 1, or finding double of 8 and subtracting 1. Help students come to the conclusion that all doubles are even and double+1 and doubles-1 are odd numbers.

Count up: If you are adding any number no matter how large to 1, 2 or 3, all you do is to count up from the big number. For example 24+3 = 27 by counting up to find the third number after 24 (25, 26, 27). Primary students can use a 100 chart or a number line to help them.

Simple Addition: It is beneficial to know the sum of 1-digit numbers by heart. This skill is necessary when adding any number.

Find Missing Number in a simple addition. Either one of the addends or the sum is missing and students have to find the missing numbers. This forces the students to think about what addition really means and how it is related to subtraction. It is a great starter for introducing algebra.

Count up by 10: Adding multiples of 10 is just like adding simple 1-digit numbers. For example, 40+70=110 because 4+7=11.

Count up by 100: Adding multiples of 100 is just like adding simple 1-digit numbers. For example, 500+70=1200 because 5+7=12.

Add 10: Adding 10 to any number is easy like 39 +10 = 49. On a 100 chart imagine going down one square.

Add 9: First add 10 then subtract 1. For example 76 + 9 = 85 because 76 + 10 = 86 and 86 - 1 = 85.

Add 11: First add 10 and then add 1. For example 68 + 11= 79 because 68 + 10 = 78 and 78 + 1 = 79.

Target 10: Pair up or make groups of as many numbers that add up to 10. Then find the total. This is designed to reinforce the "number bond" skills.

Remix: Break numbers to make your addends round (e.g., 5, 10, 20, etc.). For example: 8 + 9 can be thought as 8+ 2+7. In this case 9 was split into 2 and 7. 8+2=10 and 10+7=17.

Use the 100 chart to add. See the example below. Remember: 1 square down = +10 and 1 square Forward = +1

Adding 2-digit numbers: What mental math strategies are useful when adding larger numbers?

Adding 3-digit numbers: What mental math strategies do you use when adding larger numbers?

These are just a few simple strategies. There are many more strategies and in real life, we have to choose the best one for the task at hand.

Suggested Lessons or Activities:

Students can print the worksheets or quizzes for themselves or their peers whenever they are ready. After printing the worksheet they can click the eye button to reveal the answers and print the answer sheet. It is a good idea for students to use the answer sheet to mark each other.

Special Features:

full screen

date stamp

annotation for showing your work and the strategies you used

answer sheet (Click the eye button.)

printable (Exit Full Screen when ready to print. or when you want to type in the instructions and the name.)

Instructions: | | Suggested Lessons or Activities: | Special Features: | Other Related Modules and Useful Links:

© R. Mirshahi

## Instructions:

Doubles or Near Doubles: Students benefit from knowing the double facts such as 7+7=14 or 9+9=18. If you know these facts you can add near doubles such as 7+8 by finding double of 7 and adding 1, or finding double of 8 and subtracting 1. Help students come to the conclusion that all doubles are even and double+1 and doubles-1 are odd numbers.Count up: If you are adding any number no matter how large to 1, 2 or 3, all you do is to count up from the big number. For example 24+3 = 27 by counting up to find the third number after 24 (25,26,27). Primary students can use a 100 chart or a number line to help them.Simple Addition: It is beneficial to know the sum of 1-digit numbers by heart. This skill is necessary when adding any number.Find Missing Number in a simple addition. Either one of the addends or the sum is missing and students have to find the missing numbers. This forces the students to think about what addition really means and how it is related to subtraction. It is a great starter for introducing algebra.Count up by 10: Adding multiples of 10 is just like adding simple 1-digit numbers. For example, 40+70=110 because 4+7=11.Count up by 100: Adding multiples of 100 is just like adding simple 1-digit numbers. For example, 500+70=1200 because 5+7=12.Add 10: Adding 10 to any number is easy like 39 +10 = 49. On a 100 chart imagine going down one square.Add 9: First add 10 then subtract 1. For example 76 + 9 = 85 because 76 + 10 = 86 and 86 - 1 = 85.Add 11: First add 10 and then add 1. For example 68 + 11= 79 because 68 + 10 = 78 and 78 + 1 = 79.Target 10: Pair up or make groups of as many numbers that add up to 10. Then find the total. This is designed to reinforce the "number bond" skills.Remix: Break numbers to make your addends round (e.g., 5, 10, 20, etc.). For example: 8 + 9 can be thought as 8+ 2+7. In this case 9 was split into 2 and 7. 8+2=10 and 10+7=17.Use the 100 chart to add. See the example below. Remember: 1 square down = +10 and 1 square Forward = +1These are just a few simple strategies. There are many more strategies and in real life, we have to choose the best one for the task at hand.

## Suggested Lessons or Activities:

## Special Features:

## Other Related Modules and Useful Links:

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