4 x 8 = 32. Add 2 zeros.
40 x 80 = 3200
GIMME THE ANSWER
371
mental math
40000
move the decimal point to the right one space
how to do mental math useing propertys
510 divide by 52 using mental math and using long div = 9.807692307692308
GIMME THE ANSWER
5*9 = 45 so 50*90 = 4500.
197
371
You
3.4
No difference. Both require you to think it out rather than write it out.
mental math
70
You can, if you wish.