5 times 18 is 90 — with the shortcut, the division facts and a drill to make it stick
5 × 18 = 90. That is the short answer, and it is the same answer whichever way round you write the two numbers. Below is where 90 comes from, the shortcut that gets you there without counting, the division facts that travel with it, and the fastest way to move it from "I can work it out" to "I just know it".
5 × 18 = 90. Said out loud in the way most classrooms say it: Five eighteens are ninety.
18 + 18 + 18 + 18 + 18 = 90 — that is five eighteens added together.
Written the other way round the answer does not change. 18 × 5 = 90 as well, because multiplication is commutative — the order of the two factors never affects the product. That halves how many facts you actually have to learn: get 5 × 18 and you have 18 × 5 for free.
Five is half of ten. Ten eighteens are 180, and half of 180 is 90.
Every answer in the five times table ends in 0 or 5, so 90 ending in 0 is a quick sanity check.
Because one of the factors is even, the answer has to be even. 90 is, so the parity check passes.
90 is a multiple of nine — its digits add to 9, which is itself a multiple of nine.
Every multiplication fact comes with a division fact on its back. These four all say the same thing about 5, 18 and 90: 5 × 18 = 90; 18 × 5 = 90; 90 ÷ 5 = 18; 90 ÷ 18 = 5.
Learning them as one family rather than four separate things is the single biggest shortcut in times-table practice. If you can answer "90 divided by 5" as fast as you can answer "5 times 18", the fact is genuinely learned rather than just recognised.
In the 5 times table, 90 is the eighteenth step: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90.
In the 18 times table it is the fifth step instead: 18, 36, 54, 72, 90, 108, 126, 144, 162, 180, 198, 216.
Seeing the same number arrive from two directions is what makes it stick. 90 is a landmark in both rows, so whichever table you are drilling you meet it again.
5 × 17 = 85, 5 × 19 = 95, 4 × 18 = 72, 6 × 18 = 108. Those are the answers people most often give by accident when they are a beat too quick.
The gap between neighbours is worth knowing on its own: each extra five adds 5 to the running total, and each extra eighteen adds 18. So if 5 × 18 = 90 is solid, you can reach 5 × 19 by adding 5 rather than starting again.
Recognising a fact and recalling it under time pressure are different skills. A fact you can work out in four seconds still costs you four seconds every time it appears inside a longer calculation.
Short daily bursts beat long sessions: a 60-second drill every day will fix a table faster than one twenty-minute sitting a week. Mix the fact you are learning in among ones you already know so recall is being tested, not the order of a list.
5 times 18 is 90. In words, five eighteens are ninety.
18 times 5 is also 90. Swapping the two factors never changes the answer, so 18 × 5 and 5 × 18 both come to 90.
90 ÷ 5 = 18, because 5 × 18 = 90. The matching fact is 90 ÷ 18 = 5.
Five is half of ten. Ten eighteens are 180, and half of 180 is 90.
Yes. 90 is the eighteenth number in the 5 times table, and the fifth number in the 18 times table.
Every multiplication fact from 2 × 2 to 20 × 20 has its own page here, and the full grid is on the multiplication chart.