ABACUS International Math Challenge
for
3rd and 4th graders
February, 2007
(These is the last set of questions
for this year!
Please, send all your solutions in by April
30, 2007.)
A.577. Sue is drawing polygon shapes using
the lines on a square grid paper. Each shape she draws has an area of 5
square units. How many different shapes can she draw?
A.578. Heidi rolls 3 dice and adds up the
numbers on them. Them she writes down those cases when the sum is even and
greater than 8. How many different cases can she write down?
A.579. How many
a) squares
b) rectangles
can you see on the following diagram?
A.580. Cecilia has 1 white, 2 red, 3 blue,
and 4 green building block cubes, all of them of the same size. Randomly,
she picked up 5 of them and made the following statements about those she
picked up:
a) not all of them are the same color
b) none of them are blue or green
c) I have more green than white cubes in my hands
d) no two of them are the same color
e) I have only green and white cubes in my hands
f) I have only green cubes in my hands.
Decide which statements are "true for sure", "false for
sure", and which ones are "maybe true" but not for sure"?
A.581. Fill in the blank fields by writing
either 2, 5, or 10 into them so that the sum of the numbers in each column
and each row is 22.
A.582. Olivia has a wooden cube with 4
cm long edges. She painted it blue on the out side, then cut it up to 1x1x1
cm cubes. How many little cubes have
a) 4 blue sides
b) 3 blue sides
c) 2 blue sides
d) 1 blue sides
e) zero blue sides?
A.583. Divide the face of an analog clock
with two straight lines into three sections so that the sum of the numbers
in each section is the same.
A.584. Tamara rolls with 4 dice. In two
different groups, she writes down and adds up all the different 4-digit
numbers she can make using those numbers she rolled in which the product
of the digits is 6 or 8. Which sum is greater and by how much if we assume
that she got all possible such 4-digit numbers for both groups?
Please, send your solutions to: