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Grade 3 – 5Topic 5 of 5
Lesson 1.5 · Converting Mixed Numbers & Improper Fractions7 mins read

Converting Between Mixed Numbers and Improper Fractions

Before starting this lesson, it is best to first explore Unit Fractions (Lesson 1.2) ↗ and The Value of Fractions (Lesson 1.3) ↗. All fractions are built from unit fractions!

What Does an Improper Fraction Mean?

Before mastering conversions, remember that every fraction is simply a count of its unit pieces (1d):

125→ means:
12 pieces of15

Every single piece is one fifth (1/5).

74→ means:
7 pieces of14

Every single piece is one fourth (1/4).

🪙 1. The Core Secret: Think Like Money!

Converting fractions is identical to handling pocket money. You either cash in whole bills into coins or group loose coins into full bills:

A

Cashing In Wholes (Mixed → Improper)

Example: How do you turn £2 and 80p entirely into pennies?

1. Cash In Wholes
2 × 100p = 200p

2 whole pounds = 200 pennies

2. Add the Change
+ 80p

80 loose pennies you already have

Total Pennies
280p!

All in single penny units

The Connection to Fractions:

When you have 234, you cash in the 2 wholes into fourths (2 × 4 = 8 fourths), then add the 3 loose fourths to get 11 fourths (114)!

B

Grouping Loose Coins (Improper → Mixed)

Example: You have 120 loose pennies. How many whole pounds is that?

1. Group 100 Pennies
100p = £1

Takes 100p to make 1 full whole

2. Leftover Pennies
120 - 100 = 20p

20 pennies cannot make another whole

Mixed Amount
£1 & 20p

1 whole pound and 20 change

The Connection to Fractions:

When you have 125, every 5 pieces make 1 whole (5/5 = 1). 10 pieces make 2 wholes (10/5 = 2). You have 2 full wholes and 2 pieces left over225!

✂️ 2. Mixed to Improper: "Cash In the Wholes!"

Let's follow the 3-step method to convert 234 into an improper fraction:

234
1 Whole (4/4)1 Whole
1 Whole (4/4)2nd Whole
+
1/41/41/41/4Fraction Part (3 pieces)
Starting Position:

We have 2 full wholes and 3 loose pieces of 14.

Click "Step 1: Cash In!" to slice the 2 solid wholes into fourths.

1

Unit Fraction

Look at the denominator! Because the denominator is 4, the unit fraction is 14. All counting is done in fourths.

2

Cash In Wholes!

1 whole = 4 pieces. Slicing 2 wholes gives:
2 × 4 = 8 pieces of 14.

3

Add the Pieces

8 pieces from wholes + 3 loose pieces:
8 + 3 = 11 pieces → 114!

Another Example: 325

Convert 325 into an improper fraction step by step:

Step 1: Find the Unit Fraction

Because the denominator is 5, the unit fraction is 15. All counting will be in fifths.

📦 3. Improper to Mixed: "Group into Full Wholes!"

In improper fractions, you have lots of loose unit pieces. We group them into full whole containers and write whatever pieces remain as the fraction part:

125(12 pieces of 15)
Think Step by Step:
Start
0/5 = 0
0 pieces
1 Whole
5/5 = 1 whole
5 pieces filled
2 Wholes!
10/5 = 2 wholes
10 pieces filled
We have 12 pieces!
12/5 = 2 2/5
2 wholes + 2 loose

Because 10 pieces make 2 wholes, and we have 12 pieces in total: 12 - 10 = 2 loose pieces left over!

1/51/51/51/51/5Whole 1 (5/5 filled)
1/51/51/51/51/5Whole 2 (5/5 filled)
1/51/51/51/51/53rd Bar (2 pieces)
125 = 225
225
Whole Part2 full wholes
Fraction Part2 pieces of 1/5

Write the whole number beside the fraction bar:

Notice where the big 2 sits: it is centered right next to the fraction line, never up in the numerator!

The big 2 shows that 2 whole bars are completely filled. The remaining 25 sits directly beside it, representing the 2 loose pieces in the next unfinished bar.

Another Example: 74

Convert 7 quarter pieces (74) into a mixed number:

1/41/41/41/41 Whole (4/4 filled)
1/41/41/41/43 Pieces (3/4 filled)
74 = 134

4 pieces fill 1 full whole, leaving 3 pieces1 whole and 3 pieces = 134!

🧪 4. Interactive Conversion Lab

Test and convert any fraction yourself! Toggle between cashing in wholes and grouping pieces:

1 whole = 4 pieces of 14

2 × 4 = 8 pieces of 14

+3 loose pieces of 14

234
=
114
Cashing In Wholes into Unit Pieces:

(2 wholes × 4 pieces) + 3 loose pieces = 8 + 3 = 11 pieces of 14114!

1/41/41/41/4Whole 1 (4 pcs)
1/41/41/41/4Whole 2 (4 pcs)
+
1/41/41/41/4Change (3 pcs)