Respuesta :
Doubles fact is adding two addends that are the same.
1 + 1 = 2
2 + 2 = 4
3 + 3 = 9
4 + 4 = 8
5 + 5 = 10
6 + 6 = 12
7 + 7 = 14
8 + 8 = 16
9 + 9 = 18
10 + 10 = 20
Except 3 + 3; all sums are even numbers.
Doubles + 1 fact:
6 + 6 = 12
12 + 1 = 13
6 + 7 = 13
This is better explained using tokens or counters.
1 + 1 = 2
2 + 2 = 4
3 + 3 = 9
4 + 4 = 8
5 + 5 = 10
6 + 6 = 12
7 + 7 = 14
8 + 8 = 16
9 + 9 = 18
10 + 10 = 20
Except 3 + 3; all sums are even numbers.
Doubles + 1 fact:
6 + 6 = 12
12 + 1 = 13
6 + 7 = 13
This is better explained using tokens or counters.
Answer:
Doublets means when two same single digit number or two digit number are added, we get the result equal to number multiplied by 2.For Example
1+1=1×2=2
2+2=2×2=4
...............
..................
9+9=2×9=18
Now, we have to find sum Using doublets.
First Way
→6+7
=6+6+1
=2×6+1
=12+1
=13
Second way
→6+7
→7-1+7
→7+7-1
→2×7-1
→14-1
=13
