# Monthly Archives: May 2019

## DAY/DYDD 141:

The Main Challenge One of our easier Mathelona-style challenges, still utilising the four arithmetic operations. Place the eight digits 1 2 2 3 4 4 5 and 6 into the gaps so both lines work out: ◯ + ◯ = … Continue reading

## DAY/DYDD 140:

The Main Challenge Group the following numbers into three groups of three so that the sum of each of the triples are the same. What is this sum? 11 25 35 43 51 63 … Continue reading

## DAY/DYDD 139:

The Main Challenge There are two sections below, both containing ten letters, A-J. Each letter is linked to a division calculation: Section 1 D:9÷3 H:8÷2 B:12÷3 I:8÷4 A:4÷2 E:24÷6 G:15÷5 C:20÷4 F:25÷5 J:7÷7 Section 2 I:6÷2 G:6÷3 D:10÷2 E:12÷4 J:14÷7 B:20÷5 A:18÷6 … Continue reading

## DAY/DYDD 138:

The Main Challenge The two sections below both contain ten letters, A-J; each of which has a multiplication calculation assigned to it: Section 1 C:10×2 J:4×3 F:8×5 D:3×3 I:3×2 G:7×4 B:5×4 H:9×4 E:10×3 A:6×4 Section 2 B:12×2 D:6×1 G:8×3 J:5×2 … Continue reading

## DAY/DYDD 137:

The Main Challenge It is possible to use seven 5’s (5 5 5 5 5 5 and 5) once each, with the four operations + – × ÷, to make all the target numbers from 1 to 5. For instance, to … Continue reading

## DAY/DYDD 136:

The Main Challenge Can you arrive at the target number 55 by using the five numbers 1, 2, 3, 4 and 5 exactly once each, and with + – × ÷ available? The 7puzzle Challenge The playing board of the 7puzzle … Continue reading

## DAY/DYDD 135:

The Main Challenge Here’s a number trail involving 16 arithmetical steps. Start with the number 2, then: +33 divide by seven ×3 add ten percent double this add three find the square root of this +7 1/2 of this add … Continue reading

## DAY/DYDD 134:

The Main Challenge Read the following facts to work out my numerical value: I am a single digit number, If you add 6 to me I become a 2-digit number, I am an odd number, I am not a square number, … Continue reading

## DAY/DYDD 133:

The Main Challenge Group these ten numbers into five pairs so that the difference between the two numbers in each pair is divisible by 7: 6 17 28 37 45 58 64 78 … Continue reading

## DAY/DYDD 132:

The Main Challenge The 15 arithmetical steps below include percentage & fraction calculations as well as big additions & multiplications: Start with the number 28, then: subtract seventy-five percent +69 –4 1/2 of this square root of this ×15 multiply … Continue reading