Grade 4 › G4U10 Sequences

Grade 4 › G4U10 Sequences › L1
GRADE 4 · ALBERTAOUTCOME AB-G4-4P1

L1 · Arithmetic Sequences: Initial Term and Constant Change (First Five Terms)

Learning goal

“I can describe an arithmetic sequence with two facts - its initial term and its constant change - and I can build or continue its first five terms by adding or subtracting the same change every step.”

Sequence — an ordered list of numbers that follows a pattern; the order matters.
Term — one number in a sequence. The first number is the first term, the next is the second term, and so on.
Initial term — the very first term: where the sequence starts.
Constant change — the same amount added (or subtracted) to get from each term to the next, every single step. "Constant" means it never changes.
Worked example

Read the sequence: 3, 7, 11, 15, 19. Step 1: The initial term is the first number: 3. Step 2: Check the gaps between neighbours: 7 - 3 = 4; 11 - 7 = 4; 15 - 11 = 4; 19 - 15 = 4. Every gap is 4. Step 3: So the constant change is +4 (add 4 each time). A sequence whose constant change is adding or subtracting is called an arithmetic sequence. Say it plainly: two facts describe the whole sequence - where it starts, and the constant change. And you must check EVERY gap: one different gap breaks the pattern.

Check yourself — explain it

Why check every gap instead of just the first one?

Paired problem — example still visible

For the sequence 12, 15, 18, 21, 24, state the initial term and the constant change. -> Initial term 12; constant change +3 (gaps: 3, 3, 3, 3)

Faded completion — last step is yours

"Sequence: 30, 26, 22, 18. Initial term: ___. Gaps: 26 - 30 - the terms go DOWN by ___ each time, so the constant change is subtract ___" -> 30; 4; 4

Ready to practise?

10 scored questions with a 3-rung hint ladder. Mastery needs 8/10 plus both gate questions.

Start practice →Take the unit quiz