Here is a video of Adam explaining the strategy of making 10 to add and subtract.
Note that when you are adding , he will make a number bond using the larger number and adding it to the smaller number to make the number ten. i.e.: 13 + 5, I would take 5 from 13 and add it to the other 5, making 10. Then use the rest of my 13 number bond, 8, and add it to my 10. 8+10= 18. Of course I could just count on, but learning this strategy will help with larger sums.
When subtracting, say 13 – 5, I will make a number bond with the larger number, but turn it into 10 and what’s left. So 13 becomes 10 and 3, then I will take the 10 and subtract the 5, 10 – 5 = 5. Now add the numbers 5 and 3, they are what is left after the subtraction and that is the answer. Hopefully you will see this in Adam’s explanation!
IMG 1990 from KSH Kula Ha'aha'a on Vimeo.
