Ray's New Primary Arithmetic · Lesson LIII · Unit 6: Division
53. Dividing by 2
Goal: Your child knows how many times 2 is contained in each number up to 20, and uses it in story problems.
You'll need
- About 20 small counters: dried beans, buttons, pennies or pebbles (the book suggests marbles, beans or pebbles)
- A slate, small whiteboard or paper and pencil
What's in the book
The table from "2 in 2, 1 time" to "2 in 20, 10 times", with the matching facts the other way round, then story problems on buying, sharing and measures. The first has a worked solution.
The lesson, step by step
Warm up
Ask five facts from the 2 times table. Division is the times table backwards.
Build it with counters
Put out 6 beans. Ask: How many groups of 2 can you make? Make them and count the groups.
Say it the book's way: "2 in 6, 3 times."
Link to multiplying
Ask: 3 times 2 are how many? So 2 is contained in 6 three times.
Read the table
Read the table on the book page together, then alone.
Cover and recall
Cover the answers and ask the facts out of order.
Story problems
Read the problems aloud. They go like this:
How many apples, at 2 cents each, can you buy for 4 cents?
How many yards of ribbon, at 2 cents a yard, can you buy for 12 cents?
The book's answers sound like this: "You can buy as many as 2 cents are contained times in ..."
Wrap up
Your child writes three division facts and the times-table fact that goes with each.
Afterwards
Mix this table into the daily warm-up with the 2 times table.
Tip
There are two kinds of dividing: sharing ("12 shared among 3") and grouping ("how many 3s in 12"). The book uses both. Both have the same answer.
Answers to the book's problems
1. 2 apples. 2. 3 marbles. 3. 2 lemons. 4. 2 peaches. 5. 6 yards. 6. 2 oranges. 7. 8 tops. 8. 2 kites.
Worked out for this site from the scan. If a number in your copy differs, trust the book.