Читать книгу All the Math You'll Ever Need - Steve Slavin - Страница 17

What is the combined total of 9,671 and 2,859?

Solution:

Here again you're regrouping. In the ones column, 1 + 9 is 10, so put down the 0 and carry the 1. Then 7 + 5 is 12 plus 1 you carried makes 13. Put down the 3 and carry the 1. Add 6 + 8 + 1 to get 15. Put down the 5 and carry the 1. Finally, 9 + 2 + 1 is 12.