Sequences
The next number in this sequence: 2, 4, 6, 8, ___
10
2 x 2 = ?
4
5 + 4 = ?
9
10 - 3 = ?
7
The answer you get when two or more numbers are added together.
Sum
The next number in this sequence: 5, 10, 15, 20, ___
25
4 x 6 = ?
24
38 + 25 = ?
63
25 - 12 = ?
13
A letter, like 'x' or 'y', that represents a number, quantity, or value that is not known yet.
Variable
The missing number in the middle of this sequence: 10, 20, ___, 40, 50
30
3 x 12 = ?
122 + 384= ?
506
372 - 129 = ?
243
The four types of operations:
addition, subtraction, multiplication, division
The "rule" (or constant difference) for this sequence: 3, 6, 9, 12...
Add 3
426 x 3 = ?
1,278
435 + 12 + 19 + 6 = ?
472
673 - 485 - 12 - 2 = ?
174
32 means 3 x 3, which equals this number:
9
Because the sequence 2, 4, 8, 16 multiplies by a constant ratio of 2 each time, it is known as this kind of sequence.
Geometric Sequence
A farmer has 12 cows. How many legs do all of the farmer's cows have in total?
48 legs
5,476 + 2,892 = ?
8,368
8,321 - 2,396 = ?
5,925
When you are given a "first term" combined with a "rule," you have this type of definition.
recursive definition