Addition strategies

In this lesson, we will learn:

• The addition strategies of: (1) using friendly numbers with adjustment, (2) creating friendly numbers using addends, (3) adding on from left to right, and (4) adding by counting on
• Understanding adding by 9

Notes:

• Method 1: change into a "friendly" number and then adjust (by subtracting)
• Round one of the addends to the nearest multiple of 10
• Then adjust by taking away how much you rounded up by to get the answer

• Method 2: make a "friendly" number using the addends
• Use the numbers that were given for the addition equation
• Move values from one number to the other number to make a multiple of 10

• Method 3: adding from left to right
• Add by going through one place value at a time
• i.e. hundreds of 1^st # + hundreds 2^nd # + tens of 1^st # + tens of 2^nd # + . . .

• Method 4: adding by counting on
• Start with the first number, then add the second number one place value at a time