Ray's New Practical Arithmetic · Art. 49 · Unit 5: Division
25. Mixed problems
Goal: Your child chooses the right operations for story problems using all four rules.
You'll need
- The book
- A slate, small whiteboard or scrap paper
- A notebook and pencil
What's in the book
Seventeen "promiscuous" (mixed) examples using adding, subtracting, multiplying and dividing. Answers are printed.
The lesson, step by step
Warm-up
Mental: 96 + 120 + 55? 500 − 271? 12 × 15? 180 ÷ 12?
Choosing the operation
Read:
In 4 bags are $500; in the first, $96; in the second, $120 ; in the third, $55 : what sum in the 4th bag? $229.
Ask: What do we do first? (Add the three bags.) Then? (Take that from 500.)
Guided practice
Read the next problem together:
Four men paid $1265 for land : the first paid $243 ; the second $61 more than the first
Work it step by step with your child, writing each step on its own line.
Independent practice
Your child does about eight of the remaining problems, writing a short label beside each step.
Check
Answers are printed. Talk through any that went wrong: usually the wrong operation, not wrong arithmetic.
Wrap-up
Your child makes up a two-step story problem for you to solve.
Tip
"Promiscuous" here just means "mixed": problems of every kind put together.