Respuesta :
What I did was add 22 in my head to 278 to equal 300.
I then just took 620-300 = 320.
Then don't forget about the 22 you added earlier because now you need to add it to the total.
320+22= 342
OR
You can add 42 to the 278 to give you 320.
Then you can easily see that its 620-320 = 300.
Then add the 42 to the 300 to give 342
I then just took 620-300 = 320.
Then don't forget about the 22 you added earlier because now you need to add it to the total.
320+22= 342
OR
You can add 42 to the 278 to give you 320.
Then you can easily see that its 620-320 = 300.
Then add the 42 to the 300 to give 342
