Multiplying Big Numbers
Ready for a multiplication adventure?
When we multiply two 2-digit numbers, we're combining groups of tens and ones. It's like having a big box of cookies (the first number) with smaller packs inside (the second number), and we want to know how many cookies we have in total!
The Grid Method
1️⃣ Break both numbers into tens and ones
2️⃣ Multiply each part separately
3️⃣ Add all the results together
Let's Try Some Examples!
Example 1: 24 × 13
Let's use the grid method:
Now add them up: 200 + 40 + 60 + 12 = 312
Example 2: 35 × 42
Let's try the standard method:
35
×42
---
70 (35 × 2)
1400 (35 × 40)
---
1470
Imagine this as 35 rows with 42 apples in each row. That's a lot of apples!
Parent Tips 🌟
- Use real-world examples: "If we buy 12 packs of cookies with 24 cookies in each, how many cookies do we have?"
- Break it down: Help your child see that 23 × 45 is (20 × 40) + (20 × 5) + (3 × 40) + (3 × 5).
- Practice with games: Play "Multiplication War" with playing cards (remove face cards, multiply two cards).