Adding Subtracting Mentally

What is the definition of sum?

• The sum is the result of adding two or more numbers together.

• The sum is the result of dividing two or more numbers.

• The sum is the result of multiplying two or more numbers.

• The sum is the result of subtracting two or more numbers.

How do you subtract with compensation?

• Subtracting with compensation involves adding both numbers together.

• Subtracting with compensation involves multiplying both numbers together.

• Subtracting with compensation involves dividing both numbers by each other.

• Subtracting with compensation involves adjusting one or both of the numbers being subtracted to make the calculation easier.

What is the commutative property of addition?

• Changing the order of the numbers being added does not change the sum.

• The order of the numbers being added changes the sum.

• The sum of two numbers is always equal to their product.

• Adding two numbers always results in a larger sum.

when estimating, numbers that make it easier to add or subtract mentally

• compatible numbers

• midpoint

• midpoint

• interval

What is 100 more than 632?

• 732

• 600

• 532

• 700

What is 100 more than 430?

• 530

• 330

• 500

• 400

790 + 100 =

• 890

• 800

• 690

• 790

What is 100 more than 745?

• 845

• 645

• 700

• 800

870 + 100

• 200

• 800

• 770

• 970

What is 100 more than 512?

• 412

• 612

• 500

• 600