Which equations show the fact family for 9, 9, and 1? Select all that apply.
(1 point)
Responses
9−9=0
9 - 9 = 0
9×1=9
9 × 1 = 9
9÷9=1
9 ÷ 9 = 1
9+1=10
9 + 1 = 10
9+9=18
9+9=18
The equations that show the fact family for 9, 9, and 1 are:
9 - 9 = 0
9 × 1 = 9
9 ÷ 9 = 1
To determine the fact family for 9, 9, and 1, we need to find a set of equations where the numbers involved can be rearranged to form different equations. The fact family consists of three related equations: two addition or subtraction equations and one multiplication or division equation.
Let's analyze each equation:
1. 9 - 9 = 0: This equation shows subtraction, where 9 minus 9 equals 0. It is a valid equation for the given numbers.
2. 9 x 1 = 9: This equation shows multiplication, where 9 times 1 equals 9. It is a valid equation for the given numbers.
3. 9 ÷ 9 = 1: This equation shows division, where 9 divided by 9 equals 1. It is a valid equation for the given numbers.
4. 9 + 1 = 10: This equation shows addition, where 9 plus 1 equals 10. Although it involves the numbers 9 and 1, it does not form a related equation to the other two equations. Therefore, it is not part of the fact family for these numbers.
5. 9 + 9 = 18: This equation shows addition, where 9 plus 9 equals 18. Like the previous equation, it does not form a related equation to the other two equations. So, it is not part of the fact family for these numbers.
Therefore, the equations that show the fact family for 9, 9, and 1 are:
- 9 - 9 = 0
- 9 x 1 = 9
- 9 ÷ 9 = 1
The correct answers are the first three options: 9 - 9 = 0, 9 x 1 = 9, and 9 ÷ 9 = 1.