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PIMSO 2025 - Mathematics - Primary 1 - National Round

Question 1

What is the sum of 77 – 17 + 117 + 23?
  1. 190
  2. 200
  3. 210
  4. 220

Question 2

What is the result when the smallest three digits even number is added to the product of 202 and 99?
  1. 20100
  2. 20098
  3. 19998
  4. 19898

Question 3

The product 2 and 7 is 14. What is the product of 20 and 700?
  1. 720
  2. 1400
  3. 14000
  4. 17440

Question 4

What is the sum of all the numbers below? 1 + 2 + 3 + 4+ … + 24 + 25
  1. 295
  2. 300
  3. 325
  4. 335

Question 5

What is the 40th shape in the pattern below?

Question illustration
  1. Circle
  2. Square
  3. Star
  4. Triangle

Question 6

What is A in A4 x 5 = 3A0?
  1. 7
  2. 6
  3. 5
  4. Cannot be determined

Question 7

What is the hundreds’ digit in the result of the mathematical sentence below? 695 - 18 + 218 - 95 + 300
  1. 7
  2. 5
  3. 3
  4. 1

Question 8

What is the result when the biggest three-digit even number is added to smallest two-digit odd number?
  1. 998
  2. 999
  3. 1008
  4. 1009

Question 9

Cards A, B, C, and D have numbers 16, 25, 41, and 45 on it. Card A has an even number. Card B has a number that can only be divided by only two numbers Card C can be divided by 9. What is the number written on Card D?

Question illustration
  1. 16
  2. 25
  3. 41
  4. 45

Question 10

The numbers in the box below are covered with a sticker. How many digit “4” are covered?

Question illustration
  1. 8
  2. 7
  3. 6
  4. 5

Question 11

A, B, and C are the different digits of a three digits number. What is A + B - C, if A B C x 8 = 3752?
  1. 19
  2. 15
  3. 11
  4. 1

Question 12

Observe the number sentence below.

Question illustration

Find the value of

Question illustration
  1. 5
  2. 6
  3. 7
  4. 8

Question 13

What is the largest possible sum of the letters “I + C + E” in the number sentence below? (Each letter represents a distinct digit.)

Question illustration
  1. 18
  2. 17
  3. 16
  4. 15

Question 14

Based on the number sequence below, find the sum of the 14th and 15th terms. 1, 7, 3, 10, 5, 13, 7, 16, 9, 19, …
  1. 15
  2. 25
  3. 35
  4. 40

Question 15

Eight years ago, Chris’s father was 4 times as old as he. This year, his father is 60 years of age. How old is Chris now?
  1. 13
  2. 18
  3. 21
  4. 24

Question 16

Johnny has a 50-minute Math lesson every Wednesday. If it starts at 3:20 pm, what time does it end?
  1. 3:50 am
  2. 3:50 pm
  3. 4:10 am
  4. 4:10 pm

Question 17

How many triangles of different sizes are there in the figure below?

Question illustration
  1. 4
  2. 6
  3. 8
  4. 10

Question 18

Figures C and I are combined to form Figure E. How many cubes are not visible in Figure E if you look at the front?

Question illustration

Original choices: A. 3; B. 4; C. 5; D. 6.

Editorial note: the viewing direction is not marked. State your convention and explain your count; this item is manually reviewed.

Question 19

In the figure shown below, how many square tiles are needed to cover the entire surface of the trapezoid?

Question illustration
  1. 41
  2. 39
  3. 35
  4. 32

Question 20

The square is cut into 3 identical rectangles as show below. Find the total distance around each rectangle if the measure around the square is 36 m.

Question illustration
  1. 18 m
  2. 21 m
  3. 24 m
  4. 30 m