Rectangles, squares and splitting arrays
Answers are for parents and teachers.
1
How many rectangles are in a strip of 8 boxes?
8 + 7 + 6 + 5 + 4 + 3 + 2 + 1 = 36 rectangles.
2
Mina draws 7 squares and puts a diagonal in each. How many triangles are there?
7 × 2 = 14 triangles.
3
Split 6 × 9 into 6 × 5 and 6 × 4. Find the total.
6 × 5 = 30 and 6 × 4 = 24. 30 + 24 = 54, so 6 × 9 = 54.
4
Make an array of 3 rows with 8 beans in each row. Split it into two parts and write the equation.
Any correct split, for example (3 × 5) + (3 × 3) = 15 + 9 = 24.
5
Write the equation for the picture: the 4 by 7 array is split into two parts.
4 × 3 = 12 and 4 × 4 = 16. 12 + 16 = 28, so 4 × 7 = 28.