<span> Compatible numbers are numbers that look nice or friendly with each other when we do mental calculation to estimate a product, but especially a division</span>
Answer: 
Step-by-step explanation:
divided by 
is the same thing as multiplying by 
.
The equation we get is:
With this equation, we can factor each equation:
We can cancel out like terms since they would be dividing each other:
Answer:
81
Step-by-step explanation:
93-12=81
A 4 digit addends could have a 5 digit sum because of the rule of regrouping.
Regrouping is a situation where carrying and borrowing is involves. So let’s have an example
8999
<span>+5678
</span>14677
so in this example, we added 8999 to 5678.
9+8 = 17, so we bring down 7 and carry 1
9 + 7 = 16 + 1 = 17 , so again we bring down 7 carry 1
9 + 6 = 15 + 1 = 16, bring down 6 carry 1
8+5 = 13 + 1 =14, since this is our last number, bring down 14..
=> 14, 677
