6 times 3 is 18. Put the 8 in the ones place and carry the 1 ~ 6 times 5 is 30. Add the carried 1 and you have 31. Put that next to the 8. ~ 4 times 3 is 12. put the 2 under the 1 in 318 and carry the 1. ~ 4 times 5 is 20. Add the carried 1 and you have 21. ~ Put that next to the 2. Now add 318 to 2120 and you have the answer of 12438.
