Addition to 20
14+1=
15
Even or odd: 4
Even
10-5=
5
40+20=
60
70-60=
10
15+5=
Even or odd: 27
Odd
16-4=
12
54+21=
75
45-12=
33
8+9=
17
Even or odd: 259
Odd
19-3=
67+31=
98
64-27=
37
9+4=
13
o o o
o o o
o o o
= repeated addition equation?
3+3+3
14-6=
8
58+33=
91
94-79=
15
9+9=
18
How can you tell if a number is even or odd?
Look at the digit in the 1s place. It has to be able to be divided into 2 equal groups.
17-8=
9
47+19=
66
36-28=
8