Estimating Addition and Subtraction

The video tutorial covers estimating subtraction and addition by rounding numbers to the nearest ten or hundred. It begins with an introduction to estimation, followed by examples of subtracting 358 from 78 and 799 from 61 using rounding. The tutorial then transitions to addition estimation, demonstrating with examples of adding 949 to 383 and 788 to 785. The focus is on understanding rounding rules and applying them to estimate results.

What is the first step in estimating subtraction?

• Multiply the numbers.

• Round the numbers to the nearest ten.

• Add the numbers directly.

• Divide the numbers.

When estimating 358 - 78, what is 358 rounded to the nearest ten?

• 350

• 340

• 360

• 370

What is the result of rounding 78 to the nearest ten?

• 70

• 80

• 60

• 90

What is the approximate result of 358 - 78 after rounding?

• 240

• 300

• 260

• 280

Why do we use an approximate sign instead of an equal sign in estimation?

• Because it is a rule.

• Because we are finding the exact answer.

• Because we are finding an estimate, not the exact answer.

• Because it looks better.

What is the rounding rule for a number with 5 in the tens place?

• Keep the number as is.

• Double the number.

• Round up.

• Round down.

What is the rounding rule for a number with 7 in the tens place?

• Keep the number as is.

• Round up.

• Subtract 10.

• Round down.

In the example of 799 - 61, what is 799 rounded to the nearest ten?

• 790

• 800

• 810

• 780

What is the approximate result of 799 - 61 after rounding?

• 740

• 760

• 700

• 720

What is the first step in estimating addition?

• Subtract the numbers directly.

• Round the numbers to the nearest hundred.

• Multiply the numbers.

• Divide the numbers.