Adding with Doubles
I've talked before about the importance of teaching math strategies.
Teaching about doubles is one way of helping students find an anchor for their basic facts. Double equations are 1 + 1, 2 + 2, 3 + 3 etc. If a child knows doubles then they can work out one more and one less than a double equation. They also give a starting point for students to work out equations like 20 + 20, or 30 + 30.
The New Zealand Council of Educational Research says that before we teach memorisation we need to teach strategy they say
'Basic facts should not just be rote-learnt in isolation from understanding. There is little point knowing what 6 + 7 or 7 × 8 is, if the student has no concept of addition or of multiplication. Teaching needs the joint foci on developing understanding as well as memory.'
I tend to teach doubles before teaching things like facts to 10.
I started teaching this series on doubles when I knew students were secure in their knowledge of numbers to 20.
Here one of my children is working out her doubles with these clip and flip cards and the colored bead bars.
Now a different number. The dot shows whether she is correct or not. She didn't get this one correct.
It's also great to make sure our students learn to transfer this knowledge as well. I like to show other ways doubles might be presented for example showing equations with a bead bar and a numeral, presenting word problems and presenting equations with just numbers.