Answer :
The doubles fact for 8+9 = 17 is (8+8)+1 or (9+9)-1 .
What is doubles fact ?
A doubles fact is a number sentence that repeats the same addend ,
such as ,
3+3 = 6,
8 + 8 = 16.
here we have to find the doubles fact for equation 8+9,
so, 8+9 = 17
By using the fact that when a number is added to itself the result is twice to itself, as
2 + 2 = 4
6 + 6 = 12
One way :
We will solve our equation 8 + 9
We can write 9 as 8+1
Now the equation becomes :
8 + 8 + 1
using doubles fact of 8,
we get the answer 16 + 1 = 17.
2nd way:
we can write 8 as 9 - 1,
now equation becomes 9 + 9 -1
using doubles fact of 9 we get 18 - 1 = 17.
So, the doubles fact for 8+9 are (8+8)+1 or (9+9)-1.
Learn more about doubles fact using link :
https://brainly.com/question/29631557
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