Multiply numbers ending in zeroes

key notes :

🔹 Key Idea
  • Numbers that end with one or more zeroes are easy to multiply.
  • First, ignore the zeroes and multiply the non-zero digits.
  • Then, count the total zeroes in both numbers and add them to the product.
🔹 Steps to Multiply Numbers Ending in Zeroes
  • Ignore the zeroes at the end of the numbers.
  • Multiply the remaining digits.
  • Add back the zeroes to the result.
🔹 Examples

20 × 30

  • Ignore zeroes → 2 × 3 = 6
  • Add two zeroes (one from each number) → 600

400 × 50

  • Ignore zeroes → 4 × 5 = 20
  • Add three zeroes (two from 400, one from 50) → 20,000

6000 × 200

  • Ignore zeroes → 6 × 2 = 12
  • Add five zeroes (three from 6000, two from 200) → 1,200,000
🔹 Quick Rule
  • Multiplying numbers ending in zeroes = Multiply the non-zero parts × Add all zeroes at the end
🔹 Practice Problems
  • 70 × 90 = ?
  • 500 × 60 = ?
  • 300 × 4000 = ?
  • 20 × 2000 = ?
  • 800 × 700 = ?

Learn with an example

🎯 Multiply:

6,000 × 5 = _______

First, multiply the non-zero parts of the numbers:

6 × 5 = 30

Now add back the zeros at the end:

30,000

🎯 Multiply:

90 × 3 = ______

First, multiply the non-zero parts of the numbers:

9 × 3 = 27

Now add back the zeros at the end:

270

✈️ Multiply: 8 × 700 = _____

First, multiply the non-zero parts of the numbers:

8 × 7 = 56

Now add back the zeroes at the end:

5,600

✈️ Multiply: 400 × 2 = _____

First, multiply the non-zero parts of the numbers:

4 × 2 = 8

Now add back the zeroes at the end:

800

✈️ Multiply: 90 × 5 = ______

First, multiply the non-zero parts of the numbers:

9 × 5 = 45

Now add back the zeroes at the end:

450

Let’s practice!