Week 7 of 8
Week 7
4th Grade → 5th Grade · Angles measure and Reading comprehension
Math
Finding Unknown Angles
Finding a missing angle when a big angle is split into parts: the parts add up to the whole angle. Fourth grade, alongside measuring with a protractor.
The mistake to watch for. Adding the two known numbers instead of subtracting one part from the whole angle.
How to help. Draw the big angle and mark the split. Write the whole, the part you know, and a box for the part you do not know.
A worked example
A 90° angle is split into two parts, and one part is 35°. The parts must add up to 90°, so the other part is 90° − 35° = 55°.
Words for this week
- angle
- The space between two lines that meet at a point, measured in degrees.
- degree
- The unit for measuring angles. A square corner is 90 degrees (90°).
- protractor
- A tool shaped like a half circle that is used to measure and draw angles.
- subtract
- To take one number away from another to find how many are left.
- whole
- All of something. In 3 + 4 = 7, the whole is 7.
Read this week
Alabama
A short places article from our Learn library, chosen for this reading level. Read it together, then ask your child to tell you one new thing they learned.