Carlos noticed a pattern in
doubles-plus-3 facts.
3+ 6 = 9
4 + 7 = 11
5 + 8 = 13
6+9= 15
7+ 10 = 17
8 + 11 = 19
a. Are the sums of doubles-plus-3
facts always even or always odd?
b. Explain why the pattern works.
a. The sums are always even.
b. Doubles facts are either an odd plus an odd number or an even plus
an even number. Both of those sums are odd. A double plus 3 is an
even plus an odd, which is always even. |