## 3rd and 4th Grade, October, 2019

A.1257. Place a set of parentheses in each of the following equalities so that they are true:

a) 30-12:3+2×2=10

b) 30-12:3+2×2=18

c) 30-12:3+2×2=56

A.1258. Yuria put the following diagram on the board and asked her classmates how many quadrilaterals they see on the picture. How many do you see?

A.1259. The following masks are in a logical order. Which numbered mask goes in the place of the question mark?

A.1260. Marlon asked the following question from his classmates: I made this square using 12 pieces of matches. Using all 12 pieces of matches, create

a) 2

b) 3

c) 4 squares on the table.

A.1261. If you fold the following grids, you can make a cube out of each of them. The sum of the numbers on the opposite sides of some of the cubes is divisible by 5. Find those cubes and those sums.

A.1262. How many 2-digit numbers have different even digits?

A.1263. In the following diagram you can see 3 balances. Based on the first 3 measurements, how many pieces of cherries can balance an apple?

A.1264. In how many 4-digit numbers is the sum of the digits 4?