4th grade · Math · Unit 7 of 12
Equations
Find the mystery number
What your child practices
Solving one-step equations with a box or letter for the unknown, using all four operations, and matching equations to word problems.
Minnesota K-12 Academic Standards benchmark: 4.3.6.1; 4.3.5.9 · finding a missing value in a number sentence and solving multi-step problems
How we explain it
Children can open this short lesson before they practice.
- An equation says two things are equal.
- Use the opposite operation to find the missing number.
- Check by putting your answer back in.
Example: ☐ + 7 = 15. What is ☐? Opposite of adding 7 is subtracting 7. 15 − 7 = 8. Answer: 8
Equations in Minnesota
In the Minnesota K-12 Academic Standards, this is unit 7 of 12 in 4th grade Math, after Patterns & Tables and before Polygons & Perimeter.
Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
What number goes in the box?
5 × = 20
answer box
4
Hint: What times 5 makes 20? Divide to find it: 20 ÷ 5.
Question 2
What number goes in the box?
775 + = 847
answer box
72
Hint: What do you add to 775 to make 847? Subtract to find it: 847 − 775.
Question 3
What number makes both sides equal?
8 × 4 = + 8
answer box
24
Hint: The = sign means both sides are worth the same. The left side is 8 × 4 = 32. What plus 8 makes 32?
Question 4
What number goes in the box?
− 322 = 324
answer box
646
Hint: Work backwards: you took away 322 and had 324 left. Add 322 back on to 324.
Question 5
What number goes in the box?
÷ 5 = 7
- 30
- 40
- 12
- 35
35
Hint: Work backwards with multiplication: if a number shared into 5 groups gives 7, the number is 7 × 5 = 35.
Question 6
What number goes in the box?
24 ÷ = 3
- 8
- 7
- 9
- 3
8
Hint: 24 split into groups gives 3. Think: 3 × what number = 24? 3 × 8 = 24.