🎬 Fractions and decimals · Class 7 maths · 3:12
Fractions and decimals: Class 7 maths video
Master multiplication and division of fractions and decimals with Captain Calc. Solve real-world problems and boost Class 7 math skills easily.
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0:00 Class 7 maths. Fractions and decimals.
0:04 Welcome to Captain Calc's math headquarters!
0:07 Join our mission today to conquer fractions and decimals with superhero power.
0:13 Multiplying Fractions with Captain Calc.
0:16 To multiply two fractions, multiply the top numbers (numerators) together and bottom numbers (denominators) together.
0:25 For mixed fractions, convert them to improper fractions before multiplying.
0:30 Try this one. Multiply 2/3 × 5/7.
0:36 Step 1: Multiply numerators: 2 × 5 = 10.
0:41 Step 2: Multiply denominators: 3 × 7 = 21.
0:47 Step 3: Combine to get 10/21.
0:50 So the answer is 10/21.
0:54 Dividing Fractions using Reciprocals.
0:57 To divide by a fraction, turn the division sign into multiplication and flip the second fraction.
1:04 Flipping a fraction gives its reciprocal (for example, reciprocal of 3/4 is 4/3).
1:11 Try this one. Divide 3/4 ÷ 1/2.
1:18 Step 1: Reciprocal of 1/2 is 2/1.
1:22 Step 2: Multiply 3/4 × 2/1 = 6/4.
1:28 Step 3: Simplify 6/4 to get 3/2.
1:33 So the answer is 3/2.
1:36 Multiplying Decimals.
1:38 Multiply decimal numbers ignoring the decimal points first as whole numbers.
1:43 Count the total number of decimal places in both factors combined.
1:48 Try this one. Multiply 0.3 × 0.4.
1:54 Step 1: Multiply whole numbers: 3 × 4 = 12.
1:59 Step 2: Count decimal places: 1 place in 0.3 plus 1 place in 0.4 equals 2 total places.
2:08 Step 3: Place decimal point 2 places from the right to get 0.12.
2:14 So the answer is 0.12.
2:17 Dividing Decimals.
2:19 To divide by a decimal, make the divisor a whole number by multiplying both dividend and divisor by 10, 100, or 1000.
2:30 Divide the new numbers using standard division.
2:33 Try this one. Divide 4.5 ÷ 9.
2:39 Step 1: Divide 45 by 9 to get 5.
2:43 Step 2: Since 4.5 has 1 decimal place, quotient has 1 decimal place.
2:50 Step 3: Answer is 0.5.
2:53 So the answer is 0.5.
2:56 Your turn. What is 2 1/2 × 4/5? Pause the video, and try it.
3:05 The answer is 2.
3:07 Well done! Now try the practice and the quiz in this lesson on LearnFun.
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