40% is the change from 670 to 938
Calculation steps:
[( 938 - 670 ) ÷ 670] x 100 = 40%
Formula
Percentage change = [(938 - 670) / 670] x 100
Subtract the new number by the original number
938 - 670 = 268
268 ÷ 670 = 0.4
0.4 x 100 = 40%
Example