Let me solve each problem step by step.
Problem 1:
In 1º ESO-A there are 12 girls and 14 boys. What fraction are girls? What fraction are boys? Simplify the results.
First, I need to find the total number of students:
Total = 12 girls + 14 boys = 26 students
Fraction of girls = 12/26
To simplify: both 12 and 26 can be divided by 2
12 ÷ 2 = 6
26 ÷ 2 = 13
So, 12/26 = 6/13
Fraction of boys = 14/26
To simplify: both 14 and 26 can be divided by 2
14 ÷ 2 = 7
26 ÷ 2 = 13
So, 14/26 = 7/13
Check: 6/13 + 7/13 = 13/13 = 1 ✓
Problem 2:
Mary has 25 pencils. Five of them are red, 8 of them are blue, 10 are green and the remainder are black. What fraction of pencils are black?
First, let me find how many black pencils there are:
Red + Blue + Green = 5 + 8 + 10 = 23 pencils
Black pencils = Total - (Red + Blue + Green) = 25 - 23 = 2 pencils
Now I'll find all fractions:
- Fraction of red pencils = 5/25 = 1/5 (dividing both by 5)
- Fraction of blue pencils = 8/25 (already simplified)
- Fraction of green pencils = 10/25 = 2/5 (dividing both by 5)
- Fraction of black pencils = 2/25 (already simplified)
Check: 1/5 + 8/25 + 2/5 + 2/25
= 5/25 + 8/25 + 10/25 + 2/25
= 25/25 = 1 ✓
Problem 3:
Luis and Conchi ordered a pizza cut into 8 equal pieces. Luis ate 3 pieces and Conchi ate 4 pieces. What fraction did Luis eat? And Conchi? What fraction is left?
Total pieces = 8
Fraction Luis ate = 3/8 (already simplified)
Fraction Conchi ate = 4/8 = 1/2 (dividing both by 4)
Pieces eaten = 3 + 4 = 7 pieces
Pieces left = 8 - 7 = 1 piece
Fraction left = 1/8
Check: 3/8 + 4/8 + 1/8 = 8/8 = 1 ✓
Final Answer:
Problem 1:
- Fraction of girls → 12/26 = 6/13
- Fraction of boys → 14/26 = 7/13
Problem 2:
- Fraction of red pencils → 5/25 = 1/5
- Fraction of blue pencils → 8/25
- Fraction of green pencils → 10/25 = 2/5
- Fraction of black pencils → 2/25
Problem 3:
- Fraction of pizza that Luis has eaten → 3/8
- Fraction of pizza that Conchi has eaten → 4/8 = 1/2
- Fraction of pizza has left → 1/8
Parent Tip: Review the logic above to help your child master the concept of word problems with fractions worksheet.
