Mental Math: Adding and Subtracting by Tens and Hundreds

This video tutorial by Mr. Ivar focuses on teaching second-grade students how to use mental math to add and subtract by tens and hundreds. The lesson begins with an introduction to mental math and its benefits over traditional paper-and-pencil methods. It explains how to identify whether numbers are increasing or decreasing and provides examples of adding and subtracting 100 and 10 mentally. The video concludes with exercises that require students to fill in the blanks to demonstrate their understanding of the concepts.

What does the term 'increasing' mean in the context of this math objective?

• Going up or getting bigger

• Staying the same

• Going down or becoming less

• None of the above

If you add 100 to 357, what is the result?

• 557

• 357

• 4570

• 457

When adding 100 to a number, which place values remain the same?

• Hundreds and tens

• Tens and ones

• Hundreds and ones

• All place values change

What is 100 less than 431?

• 231

• 431

• 331

• 531

If you subtract 100 from 132, what is the result?

• 32

• 132

• 232

• 12

What happens to the ones place when adding 10 to a number?

• It decreases by 1

• It stays the same

• It doubles

• It increases by 1

What is 10 more than 499?

• 409

• 489

• 599

• 509

What is 10 less than 653?

• 663

• 643

• 653

• 633

If 735 is 10 less than another number, what is that number?

• 745

• 755

• 725

• 735

What is 952 if it is 100 more than another number?

• 852

• 1052

• 752

• 952