Question

Explain how you could add 678 + 303 using mental math

Answer 1

678 + 303 = 981

Here are a few examples to get you started:
600 + 300 = 900 
78 + 3 = 81 
900 + 81 = 981
Here's another one:
678 = 600 + 70 + 8 
303 = 300 + 00 + 3 
Add the ones place = 11 
Add the tens place = 70 
Add the hundreds place = 900 
Now add 900 + 70 + 11 = 981
Hope this helps! :-)