25
8 tens.
4/-3 8
1 tens and 2 0nes
500+10+6 = 516
(3*10)+(9*1)=39
8 tens and 4 one
Oh, dude, it's like super easy. So, you start with 78, right? And then you regroup 1 ten as 10 ones. So, you take 1 from the tens place and add it to the ones place, making it 8 tens and 18 ones. See, easy peasy lemon squeezy!
If you have to have at least one group of each, there are four.
44
To take the tens place and add it to the other tens
30+14=44