🎬 Simple equations · Class 7 maths · 2:54
Simple equations: Class 7 maths video
Master simple equations in Class 7 maths. Learn to set up equations, solve them using inverse operations, and crack fun word problems with Captain Calc.
Straight after watching
Now try it yourself
Transcript
0:00 Class 7 maths. Simple equations.
0:03 Welcome to the superhero maths lab!
0:06 Captain Calc needs your help to unlock secret codes by solving simple equations.
0:12 Understanding Equations and Building Them.
0:15 An equation is a statement that two mathematical expressions are equal.
0:21 It always has an equals sign between the left hand side and right hand side.
0:26 Try this one. Write an equation for: 6 added to a number x gives 19.
0:33 Start with the unknown variable x.
0:37 Add 6 to x to get the expression x + 6.
0:41 Set the expression equal to 19.
0:44 So the answer is x + 6 = 19.
0:48 Solving Equations Using Addition and Subtraction.
0:52 To solve an equation means finding the value of the variable that makes it true.
0:57 You can isolate the variable by performing inverse operations.
1:02 Try this one. Solve the equation: x + 9 = 21
1:09 To isolate x, subtract 9 from both sides.
1:13 x = 21 - 9
1:16 x = 12
1:18 So the answer is x = 12.
1:22 Solving Equations with Multiplication and Division.
1:26 Division undoes multiplication, and multiplication undoes division.
1:31 When moving a term from one side to another, change its operation to the inverse.
1:37 Try this one. Solve: 6x = 42
1:43 Divide both sides by 6 to isolate x.
1:46 x = 42 ÷ 6
1:50 x = 7
1:52 So the answer is x = 7.
1:55 Solving Real-Life Word Problems.
1:58 Read the word problem to identify what unknown quantity you need to find.
2:04 Assign a variable to the unknown value.
2:07 Try this one. Aarav has 4 more than twice the number of marbles Rohan has. If Aarav has 24 marbles, how many does Rohan have?
2:18 Let Rohan have m marbles.
2:21 Aarav has 2m + 4 marbles.
2:23 Equation: 2m + 4 = 24.
2:27 Subtract 4: 2m = 20.
2:30 Divide by 2: m = 10.
2:33 So the answer is 10.
2:36 Your turn. Write an equation: 7 times a number z gives 56. Pause the video, and try it.
2:45 The answer is 7z = 56.
2:49 Well done! Now try the practice and the quiz in this lesson on LearnFun.
More videos
Watch next
0:51🎬 About LearnFun · All agesLearnFun in 50 secondsA calm tour: maths, coding, the Rubik's Cube, games and live classes.
1:31📐 Geometry · Ages 9 to 14Why do a triangle's angles add up to 180°?Tear off the corners and they make a straight line, every time.
1:30🪜 Geometry · Ages 12 to 15Pythagoras: why a² + b² = c²Count the squares, then prove it by sliding four triangles.