Stamp Game Multiplication
With stamps, multiplying means building the very same number several times and sliding the rows together. The child discovers that multiplication is just addition in a hurry — the same addend over and over.
Materials
- The stamp game (or homemade cardstock stamps)
- Slips of paper with problems like 1,234 × 3 (keep answers under 10,000)
- Pencil and paper
No materials at home? Use the virtual Stamp Game.
Before this lesson
Aims
Direct
- To multiply a multi-digit number by a single digit using repeated rows of stamps
- To see multiplication as repeated addition of the same number
Indirect
- Preparation for written multiplication and, later, the checkerboard
- Motivation for memorizing the multiplication facts — counting nine rows of stamps is slow!
Presentation
- 1 Write 1,234 × 3 on a slip and read it together.This says one thousand, two hundred thirty-four — taken three times.
- 2 Your child builds 1,234 in stamp columns. Then builds it again in a row below. Then a third time.
- 3 Pause and look at the three rows together.Three rows, and every row is exactly the same. That is what multiplication means.
- 4 Slide the columns together starting from the units, exactly as in addition. The units column now holds twelve.
- 5 Trade ten units for a 10 stamp. The tens column reaches ten — trade again. Continue until every column reads nine or less.Whenever a column reaches ten, we trade — just like in addition.
- 6 Read the product: 3,702. Write it under the problem.
- 7 On paper, write 1,234 + 1,234 + 1,234 next to 1,234 × 3 and work both. Same answer.Multiplication is adding the same number again and again — the × just says it faster.
Points of interest
- Rows that must match exactly — a wrong row jumps out at the eye
- How quickly the table fills when the number is taken 4 times
- The moment a trade in one column tips the next column over ten as well
Control of error
- The rows can be compared before combining — every row must look identical
- A finished column may never hold ten or more stamps
- On the virtual material, Check recounts every column of the combined result
Vocabulary
- multiplicand (the number taken)
- multiplier (how many times)
- product
- times
- row
Variations
- Multiply the same number by 2, then 3, then 4 on successive days and compare the growing products
- Let your child choose the multiplicand and roll a die (2–4) for the multiplier
Extensions
- Predict the units digit of the product before building — the multiplication facts start to matter
- Write the repeated-addition form beside each problem solved
Follow-up work (pencil & paper)
- Print multiplication problems (multi-digit times one digit). Your child solves each with stamps and records the product.Printable: Multi-Digit Operations
- For each problem solved with stamps, your child writes the matching repeated addition (1,234 × 3 = 1,234 + 1,234 + 1,234) underneath in pencil.
What comes next
Stamp Game Division completes the four operations: instead of building a number several times, one number is shared fairly among skittles. After division, the small bead frame carries abstraction further.
Next in this strand: Stamp Game Division