TIMO 2021 Grade 4 Preliminary Set 5

Refer to the pattern below, find the 30th figure in the sequence. ■■●×▲■■●×▲■…

The sum of father’s and mother’s ages is currently 79. If the age of father 4 years later is the same as the age of mother 7 years later, how old is mother now?

Grandmother’s age this year adds 4, multiples 7, minuses 79 and then divides by 10. The result will be 60 years old. How old is Ming’s grandmother this year?

Now is Saturday 1st September. In the same year, Hong Kong International Science Olympiad will be held on 16th December. How many day(s) is / are remaining to hold the event?

Now we add 2 numbers A and B. The tens digit of A is written from 4 correctly to 8 wrongly and the hundreds digit of B is written from 6 correctly to 2 wrongly. The wrong sum is 7328. What is the correct sum?

Find the value of $10+11+12$+...+$28+29+30$.

Find the value of 50×$209+209$×$30+209$×20.

Find the value of 2400÷$8+3200$÷$4+4000$÷10.

Find the value of 192÷$8+192$÷$16+192$÷32.

Find the value of $243+123+998+247+757+2+753+877$.

If a 9-digit number 20180513A is divisible by 8, find the value of A.

Find the unit digit of A. $A=4$×4×4×...×4×6×6×6×...×6 (25 factors 4 and 12 factors 6).

How many positive integers is 100 divisible by?

The difference of A and B is 280. A is 3 times of B. Find the value of A.

How many 2-digit numbers divisible by 7 are there?

How many rectangle(s) is / are there in the figure below?

The area of a rectangle is 20. The length is 5 times as the width. Find its perimeter.

The perimeter of an equilateral triangle is 42. Find the value of the side length.

How many edges does a cube have?

At most how many parts can we divide a circle by using 5 straight lines?