Answer:
The desired expression is 19 x (3 tens) = 19 x 30 = 570
So, the greatest ten = 3 (tens)
Step-by-step explanation:
Let us check each tens.
19 x (1 ten) = 19 x 10 = 190
19 x (2 tens) = 19 x 20 = 380
19 x (3 tens) = 19 x 30 = 570
19 x (4 tens) = 19 x 40 = 760
But, here 760 is OVER the given term 684.
and 570 is the nearest value to the value 684.
So, the desired expression is 19 x (3 tens) = 19 x 30 = 570