21
21
1, 1, 331.1, 1.1, 32.8 1.01, 1.01, 3.98
Subtract a negative 1. 19 - (-1) = 20
The missing addend is 1.
A number added to another number is called an addend, and the result of the addition is called the sum. 1+4=5 1 is an addend 4 is an addend 5 is the sum
Difference means to subtract. 'What is the difference between a person 6 feet tall and a person 5 feet tall.' There is a 1 foot difference. (6 - 5 = 1). Normally the difference is expressed as a positive number, so you would take the larger number and subtract the smaller number.
If the fractions have the same denominator, just add or subtract the numerators. 13/20 - 9/20 = 4/20 2/5 + 1/5 = 3/5
Example: 20/17 minus 1 20/17 minus 17/17 3/17
13/20 - 3/5 = 13/20 - 12/20 = 1/20
4
There are millions of combinations of numbers with a difference of 9. 9 and 0, 10 and 1, 11 and 2, 12 and 3, and so on. The difference is the answer that you get when you subtract two numbers, so any numbers that subtract to an answer of 9 will work.
You subtract any two adjacent numbers in the sequence. For example, in the sequence (1, 4, 7, 10, ...), you can subtract 4 - 1, or 7 - 4, or 10 - 7; in any case you will get 3, which is the common difference.