Today is rung 2 of 4 on this topic
Order of operations and writing expressions
Can do: Evaluates expressions with brackets and multiple operations, and writes an expression from a word description.
Why it matters
It's the grammar of algebra. Getting it wrong makes every later equation unreliable in a way that's hard to diagnose.
What it looks like when it's wobbly
Works strictly left to right, so 2 + 3 ร 4 becomes 20.
โฑ๏ธ Two-minute check
"2 + 3 ร 4? And (2 + 3) ร 4? Now write an expression for 'add 5 to a number then double it'."
Solid looks like: 14, 20, and 2 ร (n + 5) with the brackets in the right place.
The full activity for this topic ยท 15 minutes
Brackets Change the Answer
- 1Write one expression and evaluate it two ways โ with and without brackets.
- 2Check both on a calculator so the machine settles the argument, not you.
- 3Give a target number and a set of digits, and let them insert operations and brackets to hit it.
- 4Translate word descriptions into expressions, watching for where brackets are needed.
- 5Do the reverse: read an expression aloud in words.
If it's too hard
Two operations only, always with brackets shown.
If it's too easy
Expressions with exponents, and word problems where the bracket placement decides the answer.
Say this
"Multiplication doesn't wait its turn. What has to happen before anything else?"
