Simple Addition Strategies

By: Haley Harr

Counting-On

• Counting-on is as simple as it sounds! Remember as a kid and you were asked to add 3 to 5, so you helped up 5 fingers and added a finger each time you counted. 5.. 6…7…8.

• Kids normally use this with +1, +2, +3• Can think of it as 5; 6,7,8

Doubles +/- 1, +/-2

• Doubles is when a kid makes a problem into a double

• Say we have 6+8… Well couldn’t it be 6+6+2?• 6+(8-2)+2=6+6+2=14

• Kids find it easy to compute doubles.

Make a Ten (Base)

• Making a base requires a child to change a problem so that it’s multiple of 10 + another number.

• What does this look like?• 9 + 6 (9+1) + (6-1) 10 + 5 = 15

Compensation

• Compensation is when students take two numbers that around doubles and turn them into doubles.

• This is NOT the same as Doubles +/- 1, +/- 2!!• What does this look like?• 5 + 7 (5+1) + (7-1) 6 + 6 = 12

Doubles VS Compensation

• What is the main difference??• Doubles has 3 “reactants” while compensation

has only 2.• Doubles: 6+8 6+6+2 = 12• Compensation: 5+7 6+6 = 12

GAUSSIAN ADDITION STRATEGIES

When is it used?

• Adding a constant amount each time.• Adding 2, 3, 5, etc.

• It’s consecutive constant amount.• Given each term, but you want to know the total sum.• I know the last term in the sequence• Ex:• 6 + 8 + 10 + 12 +14

Pairing

• 6 + 8 + 10 + 12 + 14

• We paired each of the numbers together, but we had one left over. Each pair adds up to 20.

Pairing (Continued)

• 2(20) + 10 = 50• 2 = # of pairs• 20 = sum of each pair• 10 = middle #• You won’t have this if the total amount of numbers is even

• 50 = total

Doubling/Halving

• 6 + 8 + 10 + 12 + 14 +14 +12 +10 + 8 + 6 20 20 20 20 20• 5(20) = 100• 5 = # of numbers/ # of pairs• 20 = sum of each pair• 100 = total (double)

• 100/2 = 50

Mean

• 6 + 8 + 10 + 12 +14 +4 + 2 + 0 - 2 - 4 10 10 10 10 10• 5(10) = 50• 5 = # of numbers• 10 = mean• 50 = total