Question

Complete the equation, and tell which property you used.7. (3 X 10) X 8 = X (10 X 8)8. 16 + 31 = 31 +9. 0 +__= 9110. 21 x__= 9 X 21Problem Solving(RealWorld11. The Metro Theater has 20 rows of seats with 18seats in each row. Tickets cost $5. The theater'sincome in dollars if all seats are sold is (20 X 18)X 5. Use properties to find the total income.12. The numbers of students in the foursixth-grade classes at Northside School are 26,19, 34, and 21. Use properties to find the totalnumber of students in the four classes.

Answer 1

7. (3 X 10) X 8 = 3 X (10 X 8)

In this case, we use the associative property of the multiplication (you can group the factors in any way).

8. 16 + 31 = 31 + 16

Commutative property.

9. 0 + 91 = 91

Identity property

10. 21 x 9 = 9 X 21

Commutative property

11. The income is (20 * 18) * 5.

We can multiply the three numbers together, using the associative property.

20 * 18 * 5 = 1800

12. In this case, we have to add each of the groups:

26 + 19 + 34 + 21 = 100

We don't need to apply any properrty in particular. We can add them in any order taking into account the commutative property.