M3.8.2 For the adult
Putting numbers in
Leila has 3 boxes of beans and 2 loose beans. Each box holds 4 beans. How many beans does she have?
What this chapter teaches
To find the value of an expression, put the number where the letter is. 3n means 3 times n, not 3 and n side by side. The perimeter formula P = 2l + 2w is an expression with two letters.
Three questions to ask
There is no one right wording. Listen for the idea.
- What is the value of 3n + 2 when n is 10?
- Why is 3n with n = 4 equal to 12 and not to 34?
- How would you find the perimeter of a rectangle 6 cm long and 4 cm wide?
After the chapter, the learner can
- Find the value of 3n + 2 when n = 4
- Use the formula P = 2l + 2w for a rectangle
What they copy into their notebook
Put the number in place of the letter. 3n means 3 × n, so n = 4 gives 12, not 34. Multiply before you add. P = 2l + 2w.