Sunday, July 5, 2015
Counting On: Adding Sums That Total Numbers Greater Than 10
She's already had quite a bit of experience adding and subtracting on number lines, and since we've now reached adding sums greater than 10, I figured it was time to teach her how to count on.
I explained that the first number was the SAYING number and the second number was the COUNTING number. (This made sense to her. When teaching her to add on a number line, I called the first number the BIG JUMP number and the second number was the TINY HOPS number. Whatever works.)
For example, for 7+4, the first number (the SAYING number) is 7, so she would say "seven" out loud. The second number (the COUNTING number) is 4, so she would hold up 4 fingers and count on (out loud) from 7. "Eight, nine, ten, eleven."
I like her thinking out loud because it helps me understand her thinking process. In an earlier post, I explained how this works with spelling too.
Right now, my daughter uses her fingers (or other counters) to do addition and subtraction. But there are some sums and differences that she has memorized because of repeated exposure, and over time, she will memorize more. She's also started to notice that certain numbers of counters can be divided into equal groups, and makes observations like, "Mommy, three groups of four makes twelve."
Math is fun. :)