Author Archives: 7puzzle

Today’s Challenge Here’s another MATHELONA challenge based on my popular number puzzles. Can you make all four lines work out arithmetically by replacing the 16 ◯’s with digits from 0 to 9?  Remember, each digit can only be inserted a maximum of … Continue reading →

Today’s Challenge If you wrote down all single-digit numbers and the factors of 80, how many different numbers would be written on your list? The 7puzzle Challenge The playing board of the 7puzzle game is a 7-by-7 grid of 49 different numbers, ranging from 2 up … Continue reading →

Today’s Challenge . . . is to arrive at the target number of 18 by adding together exactly FIVE numbers.  You are limited to using digits 1 to 5 but these can be used any number of times in each calculation. One way … Continue reading →

Today’s Challenge Try this number trail involving 14 arithmetical steps.  Start with 16, then: ÷4 one-half of this ×7 –7 ×8 add seventeen +7 1/10 of this –2 ×13 one-third of this ÷2 +43 1/7 of this What is your final answer? The 7puzzle Challenge … Continue reading →

Today’s Challenge Can you arrive at the target answer of 7 on both lines by using each of the numbers 0.4, 0.5, 1 and 2 exactly once each, and with + – × ÷ available?  (◯÷◯)+(◯÷◯) = 7  [◯÷(◯×◯)]+◯ = 7 The 7puzzle Challenge … Continue reading →

Today’s Challenge Each of the ten letters, A-J, in the two sections below contains a subtraction calculation: Section 1 E:7–4   J:2–1   G:7–5   A:8–6   C:4–2   I:8–5   F:6–5   B:9–8   H:9–5   D:5–4 Section 2 I:4–3 … Continue reading →

Today’s Challenge Using the numbers 2, 3 and 6 once each, with + – × ÷ available, list the 14 target numbers from 1-30 it is mathematically possible to achieve. Click the link to find out more about our amazing best-selling board game. The 7puzzle Challenge The … Continue reading →

Today’s Challenge Your task is to arrive at the target answer of 7 in all four lines by inserting the numbers 0.5, 0.5, 2 and 3 once each. [Note:  Lines 2 & 3 contain two different methods of arriving at 7]  (◯×◯)+◯+◯ … Continue reading →

Today’s Challenge Your task is to arrive at the target answer of 7 by placing the numbers 1, 1.5, 2 and 3 into the gaps on each line:  (◯×◯)+◯+◯ = 7  (◯+◯–◯)×◯ = 7  [◯÷(◯–◯)]+◯ = 7 The 7puzzle Challenge The playing … Continue reading →

Today’s Challenge Starting with the number 70, keep on subtracting consecutive prime numbers from the previous total (2, 3, 5, …) until your answer becomes negative. What is this number? The 7puzzle Challenge The playing board of the 7puzzle game is a 7-by-7 … Continue reading →