Unknown factors and equal parts
Answers are for parents and teachers.
1
Find the unknown: 4 × ? × 5 = 100.
4 × 5 = 20, and 20 × 5 = 100, so ? = 5. Check: 4 × 5 × 5 = 100.
2
Find the unknown: ? × 10 = 900, and 3 × ? × 10 = 600.
900 ÷ 10 = 90. For the second, 3 × 10 = 30 and 30 × 20 = 600, so ? = 20.
3
Draw a rectangle and divide it into 3 equal parts. Shade one part. What is the shaded part called?
The shaded part is one third. The 3 parts must be exactly the same size.
4
Four children share one cake fairly. What fraction of the cake does each child get?
The cake is cut into 4 equal parts, so each child gets one fourth.
5
The minute hand is on the 6. How many minutes have passed since the hour? What fraction of the hour is that?
30 minutes have passed, which is a half of the hour.