Multiplication Facts: 0, 1, 2, 5, and 10

Learning your multiplication facts is much easier when you know the secret rules! The numbers 0, 1, 2, 5, and 10 all have special patterns that make multiplying them a breeze.

The Zero Rule (Multiplying by 0)

Rule: Any number multiplied by 0 is always 0. Imagine having 5 plates, but there are 0 cookies on each plate. How many cookies do you have in total? Zero! $5 \times 0 = 0$ $100 \times 0 = 0$

The Identity Rule (Multiplying by 1)

Rule: Any number multiplied by 1 stays the same. If you have 1 group of 7 apples, you just have 7 apples. $7 \times 1 = 7$ $12 \times 1 = 12$

The Doubles Rule (Multiplying by 2)

Rule: Multiplying a number by 2 is the same as doubling it (adding the number to itself). $7 \times 2 = 14$ (because $7 + 7 = 14$) $4 \times 2 = 8$ (because $4 + 4 = 8$)

The High-Five Rule (Multiplying by 5)

Rule: When you multiply by 5, count by 5s. The answer will always end in a 0 or a 5. Let's count by 5s to find $6 \times 5$: $5, 10, 15, 20, 25, 30$ $6 \times 5 = 30$

The Zero Trick (Multiplying by 10)

Rule: To multiply any whole number by 10, just write the number and add a 0 to the end of it. $8 \times 10 = 80$ $3 \times 10 = 30$

Practice Problems

Try applying the rules to solve these examples:

• $7 \times 2 = ?$ (Use the doubles rule: $7 + 7 = 14$)
• $6 \times 5 = ?$ (Count by 5s six times: $30$)
• $8 \times 10 = ?$ (Use the zero trick: write $8$, add a $0$ to get $80$)