The numbers are 12 and 24, what is the answer?
We emphasize making sense of problems and numbers rather than learning "procedures" for finding answers.
What are fact strategies? Fact strategies are what our brains do to solve the foundational math facts (0+0 through 10+10 and the associated subtraction problems 20-10 through 0-0). Of the 121 addition facts we will talk about strategies for 117 of the problems. Our goal is to have "thinking strategies" that help us solve the foundational fact equations in 3 seconds or less. Please remember that students should not be timed with math facts until they can verbalize the strategy they are using and have had time to achieve automaticity with the strategy.
The first strategy we talk about is +0. Most kids come into second grade knowing that anything +0 stays the same—that’s 21 problems right there!
Here's our Foundational Math Facts Poster with the +0 facts highlighted.
The second strategy is the +1 strategy. Any number +1 is just the next number.
And here's the +1 facts. Don't think too deeply about why 9+1 is not highlighted, possibly just put the highlights up in a different order the first year.
For the +2 facts students can also "count on" within 3 seconds. I didn't take the picture in order here, so the +2 facts will magically appear on the chart later. However, if you are keeping count we are up to 57 facts with just these three strategies, almost half way!
Next we introduce the "friendly tens" or "ten pairs." These are the facts that add up to 10.
The students learn games like "Tens Go Fish" and "Pyramid" to practice the friendly tens facts. Next we work on doubles.
The lower doubles facts tend to be easy for kids to remember. We have "mini Rek-n-Reks" to practice doubles. Once kids know their friendly tens and doubles they start working on near friendly tens and doubles + or - 1.
Here are the doubles + and - 1. For example 6+7 can be thought of as 6+6=12 and 12+1=13.
Near Friendly Tens
If I know that 3+7=10 then 4+7=11.
Probably before this time your child will have mastered all the +10 facts because you've been practicing skip counting by 10 from any number.
The +9 strategy usually involves students thinking about the 9 being 10 and then taking one away. In my head I say, "Back one for nines."
Once students have the +9 strategy figured out, they can do the same thing for 8, they just need to "move 2." For example, if I am adding 8+5, I can think about giving the 8 two from the 5 and then I'd have 10 + 3.
And now we're down to just 4 facts out of the 121 that we don't have a "strategy" for. Although when you look at the facts, I bet you do have a strategy. (Did you notice the +2s magically appeared?)
As of the beginning of October we have talked about +0, +1, +2, friendly tens, and +10s. Your child has a variety of ways they are practicing these facts. We use ten frames a lot. I want this visual image in your child's brain so that they can manipulate the numbers in their brains quickly. Here are various ten frame cards.
Here's a mini Rek-n-Rek. Students can take these home to practice math facts. I think they are especially helpful for doubles and doubles +/- 1.
The top Rek-n-Rek represents 7+8. Do you see all the 5's? What does your brain do to solve 7+8? The bottom Rek-n-Rek is 6+6. What do you notice about 6+6? How far is 12 from 20? And just so it's obvious, 7+8 is a doubles +/- 1 (do you think of 7+7 is 14 +1 is 15? or maybe 8+8 is 16 -1 is 15?). And 6+6 is a doubles fact.
Hope this helps with practicing math fact strategies!