Use Known Facts To Divide A Two-Digit Number By A One-Digit Number Mentally Where There Is No Remainder.

Written by Dan

Year 3 Maths: Mental Division (2-digit ÷ 1-digit, No Remainder)

Division Decoder Challenge!

Year 3: Dividing 2-Digit Numbers Mentally

Decoder Instructions:

To mentally divide a 2-digit number by a 1-digit number (with no remainder), use your multiplication facts in reverse!
For example, to solve 24 ÷ 3:

  1. Ask yourself: “What number multiplied by 3 equals 24?”
  2. Think of your 3 times table: … 6×3=18, 7×3=21, 8×3=24.
  3. The missing number is 8.
  4. So, 24 ÷ 3 = 8!

Decoding Practice:

Codes Deciphered! You’re a Division Whiz!

Division Power! Using Your Multiplication Facts to Divide (2-Digit ÷ 1-Digit)

Hello Division Champions! Get ready to use your amazing multiplication knowledge in a super-smart way to solve division problems in your head! Today, we’re learning how to mentally divide a two-digit number by a one-digit number when there’s no remainder (meaning it divides perfectly!). The big secret? If you know your times tables, you’re already a division star!

The Super Strategy: Think Multiplication in Reverse!

Remember how multiplication and division are inverse operations (opposites that undo each other)? This is your key! When you see a division problem, you can flip it around and think of it as a missing number multiplication problem.

Let’s Solve: 56 ÷ 4

Here’s how to use your known facts:

  • The Problem: We want to solve 56 ÷ 4.
  • Think Multiplication: Ask yourself, “What number multiplied by 4 equals 56?” or “? × 4 = 56“.
  • Use Your Times Table Knowledge: Go through your 4 times table (or think about tricks like “double-double”):
    • 4 × 10 = 40 (too small)
    • 4 × 11 = 44 (getting closer)
    • 4 × 12 = 48 (still closer)
    • 4 × 13 = (4 × 10) + (4 × 3) = 40 + 12 = 52 (very close!)
    • 4 × 14 = (4 × 10) + (4 × 4) = 40 + 16 = 56 (That’s it!)
  • The Answer: Since 14 × 4 = 56, then 56 ÷ 4 = 14.

Another Strategy: Partitioning (Breaking It Down) – For Trickier Ones! Sometimes the number is a bit big to find in your times tables straight away. You can partition (break apart) the two-digit number into friendly multiples of your divisor.

Let’s Solve: 42 ÷ 3

  • The Problem: 42 ÷ 3. (Hmm, 42 isn’t obviously in the 3 times table up to 10×3 or 12×3 for everyone yet!)
  • Step 1: Partition 42 into friendly numbers for dividing by 3. We know 30 is easy to divide by 3 (30 = 10 × 3).
    • So, let’s split 42 into 30 and what’s left? 42 − 30 = 12.
    • So, 42 = 30 + 12.
  • Step 2: Divide each part by 3.
    • 30 ÷ 3 = 10 (because 10 × 3 = 30).
    • 12 ÷ 3 = 4 (because 4 × 3 = 12).
  • Step 3: Add your answers together.
    • 10 + 4 = 14.
  • The Answer: So, 42 ÷ 3 = 14.

Choose the strategy that works best for you – often “thinking multiplication” is the quickest if you know your facts well!

Practice Your Smart Mental Division! (18 Challenges)

Ready to use your known facts to solve these division puzzles? For each problem below, think about the related multiplication fact or try partitioning if it helps. All these answers will be whole numbers!

(Your web app with the 18 questions will go here. Questions should be like “48 ÷ 4 =”, “75 ÷ 5 =”, “51 ÷ 3 =”, where answers are whole numbers.)

Why is This Mental Division Skill So Cool?

  • Leverages Your Times Table Power: It makes all that times table practice really pay off!
  • Super Fast for Mental Calculations: It’s often quicker than reaching for a calculator for these types of sums.
  • Builds Confidence in Division: Knowing you can use what you already know makes division less scary.
  • Great for Problem Solving: Many real-world problems involve dividing smaller numbers.

Tips for Grown-Ups: Helping with Division Using Known Facts

This mental division strategy relies heavily on a child’s fluency with multiplication facts and their understanding of multiplication and division as inverse operations.

  • Strong Multiplication Recall is Key: Consistent practice of times tables is essential. If a child knows 6 × 7 = 42, then 42 ÷ 7 is much easier.
  • Constantly Ask “What Times…?”: For a problem like 36 ÷ 4, always prompt, “What number times 4 equals 36?”
  • Use Fact Families: Write out the related multiplication and division facts for a set of numbers (e.g., 6, 7, 42) to reinforce the connection.
  • Introduce Partitioning Gently: The partitioning strategy for division can be very powerful but might be more complex for some. Introduce it with very friendly numbers first (e.g., 48 ÷ 4 as (40÷4) + (8÷4)).
  • No Remainders (For Now!): Reassure children that all the problems on this page will divide perfectly, so they are looking for a whole number answer.

About The Author

I'm Dan Higgins, one of the faces behind The Teaching Couple. With 15 years in the education sector and a decade as a teacher, I've witnessed the highs and lows of school life. Over the years, my passion for supporting fellow teachers and making school more bearable has grown. The Teaching Couple is my platform to share strategies, tips, and insights from my journey. Together, we can shape a better school experience for all.

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