Add Three 1-Digit Numbers
π Make a number sandwich! Adding three numbers is easy if you squish two of them together first to make a friendlier number.
Do this: Read the concept below, then try the quiz or activity.
Concept
When you see a problem like 4 + 6 + 5, don't try to add all three at exactly the same time. Turn it into a sandwich!
π― The "Squish Two First" Strategy: You get to choose WHICH two numbers you want to add first! Look for special pairs. 1. Look for a 10! Do you see two numbers that make 10? Yes! 4 and 6. 2. Squish them: Add 4 + 6 = 10. 3. Add the leftovers: Now you are just adding 10 + 5. 4. Answer: 10 + 5 = 15! So, 4 + 6 + 5 = 15.
π― Look for Doubles! What if the problem is 3 + 8 + 3? 1. Find the double! 3 and 3. 2. Squish them: 3 + 3 = 6. 3. Add the leftover: 6 + 8 = 14!
Try it
Squish the numbers together!
Instructions: Find two easy numbers to add first, then add the third.
Problem 1: 2 + 8 + 7 = ? * Step 1: Find the 10! (2 + 8 = 10) * Step 2: Add the 7! (10 + 7 = ___) * Answer: ___
Problem 2: 5 + 9 + 5 = ? * Step 1: Find the double! ( ___ + ___ = ___ ) * Step 2: Add the 9! * Answer: ___
Problem 3: 4 + 4 + 6 = ? * (You can make a double, OR you can make a 10! You pick!) * Answer: ___
Problem 4: 7 + 2 + 1 = ? * Answer: ___