Comparative Relational Thinking Addition

765 = 756 5 = 3 + 2 FALSE TRUE Let’s Review Are these equations true or false? 5 = 3 + 2 765 = 756 How do you know? Talk me through your thinking… FALSE TRUE

How do you know the equation is true? Let’s Review Are these equations true or false? 4 + 6 = 3 + 7 4 + 2 = 5 How do you know the equation is true? Talk me through your thinking… FALSE TRUE

How do you know the equation is true? Let’s Review Fill in the blank 4 + 6 = 8 + __ 17 + __= 20 3 + 5 = n + 5 How do you know the equation is true? How did you solve? 2 n = 3 3

What strategies do you use to add? Let’s Review What strategies do you use to add? Count All Make Doubles Friendly Numbers Make a Ten Count On

Why do Friendly Numbers work? 17 + 8 Let’s think about an easy problem. 1 2 3 4 5 6 7 8 I will use the count up strategy first! 17 + 8 = 25

Why do Friendly Numbers work? 17 + 8 Let’s think about an easy problem. Think 8 - 3 = 5, Add 5 more Add 3 to make 20 3 5 Now with friendly numbers… Notice… 3 hops plus 5 hops is equal to 8!!! 17 + 8 = 25

Think about using Friendly Numbers to add… -3 = 43 +3 = 30 27 + 46 Then I add 30 and 43 to find the sum. 30 + 43 = 73 If I add 3 to 27, then I need to take 3 from 46…46-3 = 43 I like to add with multiples of 10, so… I need to add 3 to 27 to make 30. The answer is 73!

Using Friendly Numbers in Comparative Relational Thinking -4 = 13 +4 = 32 Let’s determine if this equation is TRUE or FALSE. 28 + 17 = 32 + 13 28 + 17 = 32 + 13 +4 -4 32 + 13 = 32 + 13 If you add 4 to the 28, you need to take 4 from the 17. You can use friendly numbers. Instead of making a 10, change one addend on one side to match the other side. It does not matter which addend is matched… BOTH addends MATCH, so it is TRUE!!! 17 – 4 is 13. So, I can add 4 to 28 to get 32? I don’t want to solve… I just want to COMPARE

Then I would subtract the value I added. Using Friendly Numbers in Comparative Relational Thinking to find an Unknown Find the unknown. 543 + 767 =  + 550 + 7 - 7 550 760 The unknown is equal to 760!! Then I would subtract the value I added. First, I change the value of one addend to be the same as the addend on the other side of the equal sign.

True or False? 937 + 580 = 940 + 583 false

True or False? 5,845 + 6,782 = 5,832 + 6,795 true

Find the missing addend. 346 + 287 = ___ + 300 287 + 13 = 300 346 – 13 = 333 Answer 333 Or 346 – 46 = 300 287 + 46 = 200 + 120 + 13 = 333

Find the missing addend.