The number 5.61 is ____ times the size of 8.38.

0.67 times.

To determine how many times 5.61 is the size of 8.38, divide 5.61 by 8.38:

5.61 / 8.38 = 0.669

To find the number of times one number is the size of another, you can divide the first number by the second number. In this case, divide 5.61 by 8.38.

Dividing 5.61 by 8.38, you get:

5.61 ÷ 8.38 ≈ 0.669

Therefore, the number 5.61 is approximately 0.669 times the size of 8.38.