The video tutorial explains how to add numbers within 20 using tens frames. It provides four examples: adding 8 plus 7, 7 plus 5, 6 plus 9, and 5 plus 9. Each example demonstrates how to use red and yellow counters to fill tens frames, regroup numbers, and simplify addition by making groups of ten. The tutorial emphasizes visualizing numbers as parts of ten to make addition easier.

What is the main strategy used in this video to add numbers within 20?

• Using a calculator

• Using tens frames and counters

• Counting on fingers

• Drawing number lines

In Example 1, how many yellow counters are initially placed on the first tens frame?

• 7

• 8

• 9

• 10

What is the final sum of 8 plus 7 in Example 1 after regrouping?

• 15

• 17

• 14

• 16

In Example 1, what is the breakdown of the number 7?

• 6 + 1

• 5 + 2

• 3 + 4

• 4 + 3

In Example 1, how many red counters are initially placed on the second tens frame?

• 6

• 7

• 9

• 8

In Example 2, how many spaces are initially blank in the first tens frame?

• 3

• 5

• 4

• 2

What is the final sum of 7 plus 5 in Example 2 after regrouping?

• 11

• 12

• 14

• 13

In Example 2, what is the breakdown of the number 5?

• 4 + 1

• 3 + 2

• 1 + 4

• 2 + 3

In Example 2, how many red counters are initially placed on the second tens frame?

• 4

• 5

• 6

• 7

In Example 3, how many yellow counters are initially placed on the first tens frame?

• 8

• 7

• 6

• 5