Mastering Mental Addition with Multiples of Ten

This video tutorial is the second lesson in a series on mental addition, focusing on adding multiples of ten. It begins with a recap of the first lesson on making ten and introduces the concept of multiples of ten. The lesson provides examples using base ten blocks and mental math tricks to add numbers quickly. Advanced strategies are discussed, including handling reversed equations. The video concludes with a practice session to reinforce the concepts learned.

What is the sum of 10 and 20?

• 40

• 10

• 20

• 30

How many rods represent the number 30 in base ten blocks?

• 2

• 4

• 1

• 3

If you add 30 and 40 using base ten blocks, how many rods will you get?

• 5

• 6

• 7

• 8

What is the mental trick to add 10 and 20 quickly?

• Add 1 and 2, then add a zero

• Add 10 and 20 directly

• Subtract 10 from 20

• Multiply 1 and 2

Using the mental trick, what is the sum of 30 and 40?

• 80

• 70

• 60

• 90

What number plus 20 equals 50?

• 10

• 40

• 20

• 30

If 10 plus something equals 40, what is the missing number?

• 20

• 40

• 10

• 30

In a reversed equation, what number plus 30 equals 50?

• 30

• 20

• 10

• 40

What is the missing number in 60 plus something equals 100?

• 40

• 60

• 30

• 50

In the speed game, what is the sum of 20 and 60?

• 100

• 90

• 80

• 70